A Musing Environment

The last two presentations in the series on climate change by Karen Street will be held on June 3rd and 17th, from 1 to 3 after meeting for worship, with a discussion of what government can do. Child care will be provided

SESSION IV: TECHNOLOGY AND POLICY June 3rd
What are the policy solutions that will make a difference? What do we look for in legislation? A look at Socolow wedges, cap and trade, and other policy issues. We will also examine the potential for technology, including efficiency, cellulosic biofuels, solar, wind, geothermal, and nuclear power.

SESSION V: NUCLEAR POWER IN TODAY’S WORLD June 17th
Does nuclear power make sense in a carbon-constrained world? Karen will present some reasons for expanding the use of nuclear power; Joe Morris, a member of Santa Monica Meeting, will present some of the reasons against. The discussion and question period will be facilitated by Elisa Barbour of Berkeley Meeting.

Berkeley Friends Meeting
2151 Vine St.
Berkeley, CA

Follow up on the previous post

There seems to be widespread acceptance of the facts of where we get our energy, and little else.

I should change the phrasing perhaps on intractable problems. This is what John Holdren, outgoing president of AAAS, said in Energy Innovation Imperative:

Global climate change is increasingly recognized as both the most dangerous and the most intractable of all of energy’s environmental impacts”indeed, the most dangerous and intractable of all of civilization’s environmental impacts, period.Distortions of this envelope [the atmosphere] of the magnitude that are underway and in prospect are likely to so badly disrupt the environmental conditions innovations and processes influenced by climate as to adversely affect every dimension of human well-being that is tied to the environment, including:

__ the productivity of farms, forests, and fisheries;
__ the geography of disease;
__ the prevalence of oppressive heat and humidity;
__ the damages to be expected from storms, floods, and wildfires;
__ the property losses to be expected from sea-level rise;
__ the expenditures that must be made on engineered environments (e.g., dams, dikes, air-conditioned spaces); and
__ the distribution and abundance of valued species as well as pests.

It is becoming clear, nonetheless, that the current level of anthropogenic interference is dangerous.

John Holdren

I am struck when I read Scot’s comments that he believes that 1) somehow we can eliminate nuclear power, and that 2) this will help protect us from nuclear war.

Actually, the use of nuclear power is expected to expand rapidly over the next half century. China intends to provide about one half wedge of nuclear power just by itself, building nuclear power capacity almost as great as exists today worldwide. From Scandinavia to the UK to South Africa to the US to Japan, new nuclear power plants are proposed.

It is fortunate then that getting rid of nuclear power does not appear to be a major mechanism for eliminating nuclear weapons.

John Holdren in his plenary address to the February meeting of the American Association for the Advancement of Science lists the two methods that people in nuclear weapons policy emphasize:

• strengthen and adequately fund the International Atomic Energy Agency, and
• zero out the nuclear weapons of all nuclear weapons states.

After all, we agree to the second it the Non-Proliferation Treaty (NPT), to:

pursue negotiations in good faith on effective measures relating to the cessation of the nuclear arms race at an early date and to nuclear disarmament…

unfortunately, without a timetable.

I agree with Scot and people pretty much everywhere in advocating that the US and Russia and other nuclear weapons states have a serious discussion before the next follow-up talks on the NPT.

2005 Campaign to Strengthen the NPT According to Arms Control Association,

Unfortunately, the once-every-five-years meeting closed without any agreed assessment or plan to bolster the treaty.

Second, Scot proposes that nuclear power has been important to the spread of nuclear weapons. Jon addresses this twice. I did an entire series on weapons and power, go to Nuclear Power in a Warming World for the links. See especially Nuclear Power and the Weapons Threat and Nuclear Proliferation– International Treaties.

Scot says,

Any nation that has the infrastructure to support civilian nuclear power plants (including the ability to obtain and enrich uranium, possibly the ability to reprocess spent fuel to obtain plutonium, trained nuclear scientists and engineers, and an industrial base to support the above) can produce nuclear weapons in a relatively short period of time, if it chooses to do so.

Of these, the most important is industrial base, although both the USSR and China developed nuclear weapons without a strong industrial base and without nuclear power.

Scot also says that the spread of nuclear power has led to greater proliferation (though the only example he gives is Iran under the cover of nuclear power claims). From the examples provided, perhaps we would be better off without nuclear medicine.

Actually, the Non-Proliferation Treaty was signed in large part because of the carrot of nuclear power (with some notable exceptions: Israel, India and Pakistan). The Nuclear Suppliers Group is an international system of monitoring dual-use technologies. This is the primary method of detecting clandestine weapons program. North Korea wanted civilian nuclear power from the USSR, signed the NPT to get it (the deal fell through), and thus agreed to aggressive monitoring.

Nuclear Suppliers Group

Khan of Pakistan helped spread nuclear weapons technology, but this did not depend on the use of nuclear power.

It is important to focus on nuclear weapons policies if we are to decrease the use of nuclear weapons. Focusing on nuclear power is a dead end.

Ruth points out that anti-nuclear weapons advocates Bethe and Blix were/are nuclear power proponents. NNadir points out the biggest nuclear weapons risk (we can’t uninvent them) and that the chances of war are likely to increase as we add climate refugees in large numbers. (My first interest in climate change came from the equality testimony — respecting everyone equally, including the right to life, and the peace testimony, taking away the occasions that lead to war, as climate change is likely to be a major cause of war this century.)

Hans Bethe

On a different subject, Joffan points out that increasing efficiency in cars may lead to their increased use, also see Rebound Effect from Better Mileage. Two responses: increasing efficiency may cost more than just burning the gas (if we neglect externalities not included in the price, like climate change and pollution and increased power of some nasty leaders). Hopefully we can find ways to internalize some of those externalities to encourage more than the altruistic to adopt those behaviors. Second, when increasing efficiency leads to lower costs, it may sometimes be useful to increase the cost of gasoline, electricity, whatever, to encourage reduced use.

Arthur feels that nuclear power plant catastrophes are worse than coal power plants in normal operation. I’m not sure how, as coal power produces about eight Chernobyls/year in the US, more than 100/year in China. See Relative Danger of Energy Sources. Arthur feels that we need to focus more on reducing the use of single occupancy vehicle. As someone who mostly travels by bus and train and bicycle, I would like to see many more people traveling by these methods, both because they are enjoyable and because as more use public transit, the faster it improves. However, even if ridership doubles in the US, it will be a tiny blip in the upward exponential of car use. Advocate for both, but don’t assume that we will be able to go without more efficient cars because everyone is getting on the bus.

Do we prefer travel by car or

other modes of transportation?

I’ve covered a number of Arthur’s points in previous blogs. Again, go to Nuclear Power in a Warming World for the links.

In the spirit of conflict resolution, promoted by Marshall Massey and others, I am wondering if there are points we can all agree on. Do we all, from both camps, agree on any or all of the following?

• 13% of energy worldwide does not come from fossil fuels: oil (41%), coal (24%), and natural gas (22%). This 13% is nuclear (6%), hydroelectric (6%), and other, primarily plants and other biopower/biofuels.

• In the US, electricity (power) is primarily fossil fuel: half coal, 20% nuclear, 18% natural gas, 3% oil, and 9% renewable. Three fourths of the renewable is hydro, 17% is biomass/waste. Geothermal (not technically renewable) and wind are each about 4% of renewables, with solar energy 0.2%.

• GHG emissions from the power sector (electricity) are growing more rapidly than GHG emissions generally.

• Scientists are correct: climate change is the most serious and intractable problem facing humans ever.

• Improving efficiency (doing the same with less energy) and changing how we live are both part of the solution.

• Other low-GHG emitting sources of electricity, such as solar, wind, and geothermal (not technically renewable) are part of the solution. This is true even though all of them will require big subsidies for many years (in solar’s case, it may be decades).

• Coal power is worse than nuclear power. We should never build another coal power plant anywhere in the world, at least without carbon capture and storage. Yet that is what the coal countries (US, China, Australia, Germany, etc) are doing and intend to continue.

• Using natural gas is more polluting than nuclear power. Note: Natural gas and hydro are the two sources of electricity now widely used to provide peak power (during parts of the day and parts of the year when more electricity is needed). But does it make sense to use natural gas for baseload (24/7) power?

• If we create enough low-GHG emitting sources of electricity, a switch to plug-in hybrids will reduce emissions from the transportation sector.

Also posted at earthwitness matters

Mechanical Engineering magazine’s article, Carbon Loaded, includes a useful graphic to help us sort out GHG emissions.

US GHG emissions

Much thanks to the author for redoing EPA information in an understandable format.

Most of these are increasing, some faster than others.

Currently coal power and nuclear power compete directly. No one is deciding whether to build a hydro or nuclear plant, a set of windmills or a nuclear plant, or a natural gas or nuclear power plant. Well, the last is possible, but do that a few times and the price of natural gas really rises. Coal and nuclear are used all day, every day. Natural gas is more expensive, so it is more often used during days or times of days when extra power is needed.

GHG emissions from coal range from 0.97 kg to 1.3 kg CO2e*/kWh, let’s call it 1 kg (2.2 pounds/kWh). Nuclear power ranges from 9 to 21 grams/kWh, let’s call that 0. How many nuclear power plants are needed to reduce ultimate atmospheric levels of greenhouse gases by 1 part per million (ppm*)?

If there is feedback (warming soils releasing carbon dioxide and methane, plants growing in dryer soils and warmer oceans holding less GHG), then GHG we add today will produce more tomorrow. But for now, let’s assume no feedback. Then 2.1 billion metric tonnes (Gt) Ce corresponds to 1 ppm Ce. Pouring 2.1 GtCe into the atmosphere raises GHG concentrations by 1 ppm. At this point, we count every ppm not added, as it reduces the amount of damage we do the Earth. And ourselves.

Let’s assume our nuclear power plant is 1,000 MW. Assuming that the plant lasts 60 years, and has a 90% capacity factor (it’s down 10% of the time for refueling and repair, 90% is average capacity factor on current plants). Then the plant will produce

1,000 x 10(6) W * 24 hours/day * 365 day/year * 60 years * 90% = 526 billion kWh.

Each kWh from coal puts 1 kg of CO2e into the atmosphere. We’ll multiply this by 12/44 to get the added weight in kg Ce. Use 1 (metric) tonne = 1,000 kg.

526 billion kWh * 1 kg CO2e/kWh * 12/44 = 140 million tonnes Ce.

To convert to ppm:

2.1 billion tonnes Ce/(140 million tonnes Ce/plant) = 14,600 MW in nuclear power.

Nuclear power plants are larger than 1,000 MW, a large one might be 1,700 MW — about 8.5 of the largest plants will lower GHG concentration by 1 ppm.

If we start 15,000 MW in nuclear power every year for the next 20 years, these power plants will reduce ultimate atmospheric GHG concentrations by more than 20 ppm. If these take an average of 4 – 5 years to build, 60 GW (60,000 MW) – 75 GW will be under construction every year.

To put this in perspective
We all agree that nuclear power is being built at a snail’s pace today: 23 GW is under construction.

In the late 1970s and early 80s, 150 GW was under construction. This was the peak of the earlier construction period, when plant construction was much slower than it would be today. Not only were new designs being worked out, but a new regulatory system as well. Add in a few nuisance lawsuits here and there. Nevertheless, the construction rate was 4 – 5 times what it would need to be to reduce GHG concentrations by 20 ppm through projects started over the next 20 years.

Perhaps in 25 years it will become obvious that solar, etc will be able to supply electricity needs soon, and no more nuclear power plants need be built. But it’s not obvious today. What is clear is that building nuclear power plants decrease atmospheric GHG concentrations.**

Nuclear

Pressurized water model

and Solar
today

Typical system

and tomorrow

Flexible Solar Cell

* Parts per million — out of every million molecules in the atmosphere, how many are CO2 or CO2e?

Greenhouse gas concentrations or emissions are often measured in CO2e or Ce, equivalent to the values if all the change were to come from CO2 or C.

** CA is adding billions of dollars in subsidies to federal subsidies to build (hopefully) 3 GW, in solar photovoltaic panels. What GHG reduction will they achieve?

Assume GHG emissions for solar are comparable to nuclear (they aren’t, PV is energy intensive to build, but energy costs are coming down). Assume as well that PV panels last 30 years and that the capacity factor for CA is 20% (night, clouds, and changing position of the sun reduce average electricity production to about 20% of theoretical).

Then if solar replaces coal, how much will our subsidies here in CA reduce GHG emissions?

3 x 10(9) W * 24 hours/day * 365 day/year * 30 years * 20% = 158 billion kWh.

158 billion kWh * 1 kg CO2e/kWh * 12/44 = 43 million tonnes Ce.

43 million tonnes Ce/2.1 billion tonnes/ppm Ce = 0.02 ppm Ce

This investment in solar power is critical to reducing electricity costs in the future, and assuring a portfolio of low-GHG sources of electricity. But it will be a while before solar, etc, will be sufficient to meet the need for low-GHG emitting sources of energy.

I would have expected a magazine devoted to mechanical engineering to go beyond my abilities to understand. Mechanical Engineering, however, is written in clear prose, with really useful graphs.

April’s issue focuses on plug-in hybrids, coal for fuel cells, reducing smog from biodiesel (biofuels, plants used to make fuels, are major NOx emitters), and Carbon Loaded. See this article for a brief summary of the Stern Review, and for its clear graphics, including where GHG emissions in the US come from.

The magazine has boucoup articles on other subjects. Heads Up looks at why dinosaurs have sinuses. Put a nozzle on it examines the advantages and disadvantages of serrated exhaust exits to reduce airplane noise. A biography of Szilard, No Einstein, includes the Szilard-Einstein effort to find a safer alternative to ammonia refrigerators. Their work was never used — the discovery of freon led to today’s refrigerator.

Nature Reports: Climate Change, a new project of Nature, is hosting a blog, Climate Feedback.

Why the need for another climate blog?

Despite a twenty fold in increase in coverage of global warming over almost two decades in the UK (and a five fold increase in the US over the same period) (see papers by Max Boykoff) , climate change remains a low priority for the mainstream media. More importantly, climate change issues remain poorly understood among even the well-informed public. Mainstream coverage of climate change often leaves readers out in the cold when it comes to separating the known from the unknown, fact from opinion and even fact from fiction. And while the contribution of human activity to climate change is well-established, the extent and timescale of future changes and how to minimise and deal with these changes remain topics of huge debate.

Check out both of these.

Ingrid from AustinPermie describes her transition to pro-nuclear through her interest in permaculture:

In permaculture, ‘permies’ as we call ourselves, are interested in the integration of various systems, and the understanding, that all of those systems are related, interconnected, and mutually dependent. Change one, you change the rest. It then becomes the domino effect. In the negative it means for example that you pollute soil (replenishing, healing the soil is one of the important goals of permies), you effect healthy micro organisms, in turn effecting depletion of nutrition and disabling the organic growing environment. Hence, when Lovelock mentioned the cycle of positive feedback, which in turn amplifies the temperature and the increase in temperature would do away with the one big hepa filter the world has (Amazon rainforest), I ‘saw’ the cycle, and understood the urge of redressing that course that Lovelock is after by endorsing nuclear energy.

This is part of her post on the rapid melting of Arctic sea ice, much faster and more alarming than models predict. To read more on the sea ice, go to National Snow and Ice Data Center.

Note: much of what Lovelock says is interesting, but not everything he says overlaps perfectly with scientific understanding.

Bob, a f/Friend (Quaker) from North Carolina discusses over a number of posts his transition to pro-nuclear power:

How will we hold ourselves to our best while death and destruction rain all around us? When refugees swarm at our borders, our doors? When there’s not enough food for our fellow humans, let alone the creatures whose habitats we’ve robbed? I was hungry and you fed me. That will apply until the end, breaking the last crust of bread with the stranger. But what if it’s a group of fifty desperate starving people?

From an earlier post:
Aldo Leopold laid the foundation for deep ecology with his land ethic: A thing is right when it preserves the integrity, stability and beauty of the biotic community. It is wrong when it tends otherwise. Nuclear power, and everything other tool of the late industrial era, needs to be judged by this overarching ethic, buttressed by the values of the world’s great religions.

Bob also discusses conspicuous consumption (my phrase), such as

unnecessary appliances, especially clothes dryers, my pet peeve.

NNadir from Daily Kos has reformed (he used to be an anti-nuclear activist). His blog is wordy, irreverent, and often touches on points that the rest of miss.

I remember reading that Galileo became interested in the heliocentric model when he noticed that discussions were converting people in only one direction: no one was leaving heliocentrism to accept the Earth as center of everything. I’ve noticed this is true about nuclear power discussions: the arguments anti-nuclear people have produced aren’t winning any converts.

From the Chicago Tribune:

Muhammad Ali, a wiry 65-year-old, has never driven a car, run an air conditioner or done much of anything that produces greenhouse gases. But on a warming planet, he is on the verge of becoming a climate refugee….

Bangladesh, which has 140 million people packed into an area a little smaller than Illinois, is one of the most vulnerable places to climate change. As the sea level slowly rises, this nation that is little more than a series of low-lying delta islands amid some of Asia’s mightiest rivers — the Ganges, Jamuna-Brahmaputra and Meghna — is seeing saltwater creep into its coastal soils and drinking water. Farmers near the Bay of Bengal who once grew rice now are raising shrimp.

Notorious for its deadly cyclones, Bangladesh is likely to face increasingly violent storms as the weather warms and see surging seas carry saltwater farther and farther up the country’s rivers, ruining soils, according to scientists.

Land disputes, many driven by erosion [caused by accelerating glacier melt and unusually heavy rains], now account for 77 percent of Bangladesh’s legal suits. In the dry northwest of the country, droughts are getting more severe. And if sea level rises by 3 feet by the turn of the century, as some scientists predict, a fifth of the country will disappear….

With so many huge rivers discharging into the ocean, the country couldn’t build dikes to hold back the sea even if it had the money, Rahman said. And though it has created virtually none of the pollution driving global warming, it is unlikely to receive the international assistance it needs to adapt to conditions created by others.

What that might mean for big polluting nations such as the United States, China and India is that “for every hundred thousand tons of carbon you emit, you have to take a Bangladeshi family,” Rahman said, only half joking. India already is building a fence along its border with Bangladesh….
Bangladesh’s government is doing what it can to prepare for coming hard times. With the help of non-profit organizations, it is testing new salt-resistant crops, building thousands of raised shelters to protect those in the path of cyclones and trying to elevate roads and bridges above rising rivers. Leaders who once insisted that the West created the problem and should clean it up “now accept we should prepare,” Nishat said.

The alternative could be ugly: insufficient food, a destabilized government, internal strife that could spread past the country’s borders, a massive exodus of climate refugees and more extremism, Rahman said.

“A person victimized and displaced will not sit idle,” he predicted. “There will be organized climate-displaced groups saying, ‘Why should you hang onto your place when I’ve lost mine and you’re the one who did this?’

“That,” he said, “is not a pleasant scenario.”

Note: while many scientists predict sea level rise of 3 feet by 2100, some mainstream scientists are predicting 3 feet by the third quarter of the century.

Bangladesh and sea level

Dhaka, Bangladesh – Dhaka and its metropolitan area have a population of 11 million

The full report (most of it) for Intergovernmental Panel on Climate Change Working Group 1: The Physical Basis is now available.

Recommendation to newbies: start with either the Summary for Policymakers or Technical Summary. These reference chapter sections that provide more information on topics that interest.

Last night a 12-year old friend and I attended the first in a free series of energy lectures in downtown Berkeley, courtesy of Lawrence Berkeley Labs. Paul Alivisatos will speak May 7 on Nanoscience at Work: Creating Energy from Sunlight, Jay Keasling June 4 on Renewable Energy from Synthetic Biology. Alivisatos and Keasling lead LBL’s Helios Project, turning sunlight into fuels.

Steven Chu, Nobel Prize winner in physics, left his field to head a national lab because his new interest is The Energy Problem: What the Helios Project Can Do about It — climate change and cellulosic biofuels. This will be the subject of an upcoming blog.

[The Nobel Prize was awarded for his method of slowing atoms down to a fraction of a degree above absolute zero. Imagine an atom that can only move left or right. Shine a laser light on it from both directions. Because of the Doppler effect, the atom will see one source of light as higher frequency, the other as lower frequency. The higher frequency light has greater momentum, and will give a larger push to the atom, slowing it down. In our 3-dimensional universe, six lasers are needed.]

LBL posts the talks, Chu’s is here.

A couple of interesting details:

• Between 50 and 100% of today’s US fuels could be produced by using agricultural waste plus growing crops on 50 million acres, a portion of land a little larger than Nebraska. This kind of crop would be ideal for degraded and marginal land. It would be low input (water and fertilizer) but help restore the soil. Note: fuel consumption is rising, so we need to find a way to bring this down through greater fuel economy, and perhaps through using plug-in hybrids, so that low-carbon electricity provides some of the energy. Also, predictions about yields in a changing climate are more iffy than we want them to be.

• Radiation release from nuclear power is less than that from coal. I knew that an operating coal plant releases 100 times more radiation than a similar size nuclear power plant. [Coal contains heavy metals — uranium, thorium, mercury and others. Uranium and thorium are the main source of the radioactivity release, but health problems from the release of mercury are of more concern than the heavy metal plus radiation from uranium + thorium.] What I missed in reading this article is that a coal power plant in normal operation releases 4 times as much radioactivity as a nuclear power plant from mining to operation to waste disposal, this number rises if radioactivity release from coal mining (unknown) is included.

• Average glacier thickness decreased 14 meters (45 feet) in the last 50 years. Gulp. The Tibetan glacier is shrinking 1.2 meters, 4 feet, each year.

The Washington Post has a whole series on faith, differing views on an entire range of topics. Here is Cizik on the environment:

Participation in [Earth Day] is an opportunity to express love for God and care for what He has created. We evangelicals call this “creation care.” Care for the entire creation — the environment and “all creatures great and small” — is a biblical obligation (Gen. 2:15). We should walk in God’s ways (Deut. 10:12) and try to inspire people by offering broader vistas of thought and service.

Can we hear the voice of the biblical prophet Ezekiel: “Is it not enough for you to drink the water? Must you also muddy the rest with your feet?” Here’s a modern-day question: Is it enough for you to enjoy a pleasant climate? Must you destroy it? Is it not enough for you to enjoy the myriad of creatures? Must you extinguish them? Major segments of the earth are dying and we are responsible. Earth’s resources are not infinite.

The comments so far are, “yes, caring for the Earth and its people is a Christian duty”, and “it is the duty of all of us”.

I just did a series of presentations in Tempe, AZ, had a wonderful time, hope to post more.

One night, the question of mercury in compact fluorescent bulbs generated a bit of discussion.

Sources of Mercury Emissions include coal power plants (utility boilers), cement, landfills, etc. The addition of mercury to the environment is declining; after peaking in 1960, emissions have fallen more than half. US emissions dropped by 1/3 just in the 1990s. This is because mercury use is less common.

The contribution of mercury from compact fluorescents is small, smaller than the contribution of incandescent bulbs lit in part by coal power.

Heavy metal poisoning can be serious, that said, I’m not sure why mercury has grabbed the public interest, though I see environmentalist groups pushing this concern. Not to mention the US government’s focus on cleaning up coal emissions of mercury, with less public discussion of the more potent killers from coal power. While coal is the single biggest contributor to mercury in the air, mercury is far down the list of coal’s sins. Carbon dioxide, causing climate change, particulates, killing some 30,000 Americans annually and hundreds of thousands of Chinese, and ozone, killing 1,000 Americans annually and ?? Chinese, certainly are more important than mercury. Incandescent bulbs use about 4 times the electricity and create 4 times the number of deaths and illnesses, of which mercury is a minor portion.

Compact fluorescent bulbs save lives.

Incandescent bulbs are costly. If your electricity is made from coal or natural gas, incandescent bulbs are important contributors to mortality rates, environmental destruction, and a small increase in mercury emissions (though larger than the contribution from compact fluorescents).

Switching your bulbs to compact fluorescent is a good idea!

Dispose of your light bulbs as specified locally. In some places, this means collecting them until other stuff is taken in for processing. In others, it means throwing compact fluorescents out with the trash, unless you generate more than 100 kg in hazardous waste/month.

How dangerous is mercury?
It, along with cadmium, arsenic, and lead, would not be commercially affordable if they had to meet the same standards as uranium. That said, avoid breaking CFL’s regularly and there shouldn’t be too much problem. The old mercury thermometers had between 10 and 800 times as much mercury as a compact fluorescent bulb. The Japanese problems with mercury poisoning from fish occurred after industrial dumping. Don’t go out of your way to eat mercury, but don’t worry too much about the levels of mercury in CFL’s either.

Why focus so much on carbon dioxide so often when there are other forcings?

1) It’s a lot easier to say carbon dioxide than radiative forcings, fewer blank looks.

Radiative forcings affect the radiation balance of the Earth. Before the industrial revolution, radiation in (light, including visible, infrared, and ultraviolet) was the same as radiation out.

Examples of direct forcings:

• CO2 and other greenhouse gases absorbs some of the infrared (a greater part of radiation out than radiation in) and re-emits it. About half is re-emitted down, rather than up.
• land-use change can increase albedo (the portion of light reflected) by removing darker trees. This is a negative feedback.

Example of indirect forcings, which alter the climate first:
• Added aerosols (gaseous suspension of fine solid or liquid particles) modify precipitation efficiency of clouds, changing the radiative property of clouds.

2) Adding all the positive and negative forcings together gives a total forcing about the same as carbon dioxide alone.

3) Carbon dioxide is the fastest growing forcing.

The IPCC 2007 Summary for Policymakers: The Physical Science (go to IPCC and download WG1–working group 1) has a more detailed figure of Radiative Forcing Components, here is a simplified version without error bars:

Estimate of 1750-2000 Climate Forcings

Interpreting the figure
The net increase in forcings from 1750 is 1.7 W/m2, the same as adding a 1.7 W bulb over every square meter of Earth, land and sea, 24 hours/day. This is just a little more than the contribution from carbon dioxide.

Methane, CH4, contributes a good chunk. Natural gas is primarily methane, leaked into the atmosphere in the process of getting any fossil fuel. Chlorofluorocarbons (which also destroy the ozone layer) and N20, (nitrous oxide, also an ozone destroying gas), primarily from nitrogen fertilizers, animal waste, and industry, and ozone are also important. Together, these gases have contributed 2/3 as much as carbon dioxide since 1750. Better control of methane emissions and banning of CFCs through much of the world are decreasing the importance of these GHGs in today’s emissions.

Methane’s contribution in the cumulative emissions figure was about 33% of carbon dioxide’s.

Methane’s current contribution is lower, about 29% as much as carbon dioxide.

Methane emissions in the US are about 1/9 of carbon dioxide emissions from burning fossil fuels.

US Methane Projections are expected to stay more or less the same even with no voluntary behavior change, and decline by 10% with voluntary changes; presumably faster declines are possible.

Changes since 1750 to stratospheric ozone have had a negative forcing, because we’ve destroyed part of the ozone layer. The ground layer ozone we’ve added has had a strong positive forcing.

About half as important as carbon dioxide is black carbon, from burning fossil fuels and biomass (eg, trees). Soot on snow has changed the reflectivity, leading to greater warming, about 0.1 W/m2. A brighter sun has added 0.1 W/m2 according to the latest IPCC report, less than the Hansen estimate.

The Earth has cooled (temporarily, anyway) because of the reflective aerosols we have added. IPCC estimates that the direct effect has been to increase how much sunlight is reflected off the Earth, an effect of -0.5 W/m2, and the indirect effect from changing cloud albedo has led to another -0.7 W/m2 change.

Feedback
Feedbacks are positive if they reinforce the direction of change, and negative if they counter it. If the temperature rises/falls, the amount of permanent snow in polar regions decreases/increases, reducing/increasing the percentage of sunlight reflected. Both represent positive feedback.

Other examples:
• A warmer climate leads to darker plants which absorb more sunlight.
• A warmer climate reduces the amount of carbon dioxide stored in trees, or in the soil.
• A warmer climate increases cloud reflectivity — this would be an example of negative feedback.

While climatologists are unsure of how important various positive and negative feedback mechanisms will be, they are confident that positive feedback will be more important than negative feedback, and that it will be significant.

There is great worry about the release of carbon dioxide (under aerobic conditions) and methane (under anaerobic) from warming soil. We are not there yet:

Global methane emissions do not yet include a substantial contribution from warming soil.

From Methane to Markets:

China, India, the United States, Brazil, Russia, and other Eurasian countries are responsible for almost half of all anthropogenic methane emissions. Methane emission sources vary significantly among countries. For example, the two key sources of methane emissions in China are coal mining and rice production. Russia emits most of its methane from natural gas and oil systems; India’s primary sources are rice and livestock production; and landfills are the largest source of U.S. methane emissions.

However, positive feedbacks (which may include methane and carbon dioxide from warming soil) are becoming increasingly important. From the IPCC 2007 Summary for Policymakers: The Physical Science:

…model studies suggest that to stabilise at 450 ppm carbon dioxide, could require that cumulative emissions over the 21st century be reduced from an average of approximately 670 [630 to 710] GtC (billion metric tonnes carbon) to approximately 490 [375 to 600] GtC.

Someone told me that she is seeing climate change skeptic commenters active everywhere, and asked if they are being paid.

I know that the skeptic comment after the IPCC report post came in through the normal spam route, without going through the main page. Add in the phony return address — is this the same as any other spam? What are the rest of you seeing?

The personal skeptics I know like to talk about their skepticism a lot; perhaps that is why I didn’t notice the big increase.

John Holdren, outgoing president of the American Association for the Advancement of Science, addressed the annual meeting on the big issues: human welfare, the environment, climate change, and nuclear proliferation. You can watch him speak or download the PowerPoint presentation from the AAAS site.

This is one of the most powerful summaries I’ve heard of how well we are succeeding in these four different areas, and what we can do differently and better.

The Stern Review on the Economics of Climate Change was released February 12.

Go to page 5 of the executive summary.

Currently, atmospheric levels of greenhouse gases (GHG) are 450 parts per million (ppm). This includes 382 ppm CO2. Relative to pre-industrial times, the temperature of the Earth has increased 0.8 C. The authors of the Stern Review feel that keeping atmospheric levels of greenhouse gases to 450 ppm is almost out of reach, and that it will cost 1% of the worldwide Gross Domestic Product to keep GHG levels to levels between 500 and 550 ppm.

Stabilization Levels and Probability Ranges for Temperature Increases

At 450 ppm carbon dioxide equivalent (CO2e), there is a 50% chance that the temperature increase relative to pre-industrial times will be 2 C or more, a 5% chance that it will anywhere from 3.8 C to more than 5 C. At 550 ppm CO2e, there is a 50% chance that temperature increase will be greater than 2.9 C, and a 5% chance that it will be grater than 3.8, perhaps much greater than 5 C. Notice that these probability models show asymmetric results — the 50% or 5% highest temperature increases are spread over a much larger range than the lowest counterparts.

On the same graph, there are burning embers: relative risks at different temperature increases of consequences for food, water, ecosystems, extreme weather events, and risks of rapid climate change and major irreversible impacts (weakening of currents or melting of the world’s large ice sheets).

These yellow to red give a sense of the results of studies and models — by the red region, large numbers of studies or models give a certain prediction. This does not mean that the collapse of the West Antarctic Ice Sheet is unlikely to happen (or be committed to) before the orange region, say.

Two recent reports have numbers scarier than the usual.

Yesterday, the Intergovernmental Panel on Climate Change released the Summary for Policy Makers: Impacts, Adaptation and Vulnerability.

Whatever your newspaper or TV summary of the summary, reading this completely through is scarier. One from each region of the world:

Africa
• Agricultural production, including access to food, in many African countries and regions is projected to be severely compromised by climate variability and change. The area suitable for agriculture, the length of growing seasons and yield potential, particularly along the margins of semi-arid and arid areas, are expected to decrease. This would further adversely affect food security and exacerbate malnutrition in the continent. In some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020.

Asia
• Freshwater availability in Central, South, East and Southeast Asia particularly in large river basins is projected to decrease due to climate change which, along with population growth and increasing demand arising from higher standards of living, could adversely affect more than a billion people by the 2050s.

Australia and New Zealand
• Significant loss of biodiversity is projected to occur by 2020 in some ecologically-rich sites including the Great Barrier Reef and Queensland Wet Tropics. Other sites at risk include Kakadu wetlands, south-west Australia, sub-Antarctic islands and the alpine areas of both countries.

Europe
• Nearly all European regions are anticipated to be negatively affected by some future impacts of climate change and these will pose challenges to many economic sectors. Climate change is expected to magnify regional differences in Europe’s natural resources and assets. Negative impacts will include increased risk of inland flash floods, and more frequent coastal flooding and increased erosion (due to storminess and sealevel rise). The great majority of organisms and ecosystems will have difficulties adapting to climate change. Mountainous areas will face glacier retreat, reduced snow cover and winter tourism, and extensive species losses (in some areas up to 60% under high emission scenarios by 2080).

Latin America
• By mid-century, increases in temperature and associated decreases in soil water are projected to lead to gradual replacement of tropical forest by savanna in eastern Amazonia. Semi-arid vegetation will tend to be replaced by arid-land vegetation. There is a risk of significant biodiversity loss through species extinction in many areas of tropical Latin America.

North America
• Coastal communities and habitats will be increasingly stressed by climate change impacts interacting with development and pollution. Population growth and the rising value of infrastructure in coastal areas increase vulnerability to climate variability and future climate change, with losses projected to increase if the intensity of tropical storms increases. Current adaptation is uneven and readiness for increased exposure is low.

Polar Regions
• In the Polar Regions, the main projected biophysical effects are reductions in thickness and extent of glaciers and ice sheets, and changes in natural ecosystems with detrimental effects on many organisms including migratory birds, mammals and higher predators. In the Arctic, additional impacts include reductions in the extent of sea ice and permafrost, increased coastal erosion, and an increase in the depth of permafrost seasonal thawing.

Small Islands
• Climate change is projected by the mid-century to reduce water resources in many small islands, e.g., in the Caribbean and Pacific, to the point where they become insufficient to meet demand during low rainfall periods.

For a light-hearted look at climate change, see the April 1 post of RealClimate:

The hypothesis begins with the simple observation that most sheep are white, and therefore have a higher albedo than the land on which they typically graze (see figure below). This effect is confirmed by the recent Sheep Radiation Budget Experiment. The next step in the chain of logic is to note that the sheep population of New Zealand has plummeted in recent years. The resulting decrease in albedo leads to an increase in absorbed Solar radiation, thus warming the planet.

Wouldn’t you love general advice to “insulate more” to be replaced by very specific recommendations from someone who has visited your home/business? Cambridge, MA is creating a program to do just that:

University, commercial, and even residential buildings will receive energy audits over the next five years to pinpoint energy inefficiencies. Property owners will then be offered low- or zero-interest loans to undertake remediation efforts ranging from replacing incandescent light bulbs with compact fluorescents to installing insulated roofs and more efficient heating and cooling systems…The Cambridge organizers said the first phase of their efforts will take five to seven years and will target about half of the 23,000 buildings in the city. The goal in that period is to reduce overall electricity use by 10 percent, and during peak hours — roughly 4 to 7 p.m. daily — by 14 percent, to 300 megawatts from 350 megawatts. The average household in Cambridge uses about 4,500 kilowatt/hours of electricity a year, costing about $800, according to city officials.

Financial help will be provided:

For example, proponents said a typical homeowner who gets a $1,100 loan to add insulation and buy a more efficient air-conditioner could reduce annual energy bills by around $250, meaning the payoff period can be four to five years.

Initially, property owners will be allowed to pocket about one-third of the energy savings from these measures, the consultants said, using the balance to repay their loans. Once the loans are fully repaid, the property owner would reap all future savings.

Biggest changes will occur outside the home:

In Cambridge, officials expect the greatest and quickest savings will come from working with universities and large commercial and industrial properties, which collectively account for 69 percent of the city’s energy consumption. Ultimately, proponents hope that all residential property owners will agree to undertake the recommended improvements.

Talk to your local legislators.

Insulated houses are cosier.