California’s Climate Change Plan – the Why

In December 2005, the California EPA sent an Energy Policy Report to the Governor and Legislature. This plan, now being discussed, recommends

  • By 2010, reduce emissions to 2000 levels, a 59 million tons reduction, 11% below Business as Usual
  • By 2020, reduce emissions to 1990 levels, a 145 million tons reduction, 25% below Business as Usual
  • By 2050, reduce emissions to 80% below 1990 levels

  • This first look at the report will look at the motivation for these recommendations. First, the carrots (all of the following come from the Climate Action Team analysis.

    Californians are

    (m)otivated by the stunning natural beauty of our coastline, inland valleys, forests and mountains, as well as by the public health and environmental challenges brought on by increasing levels of pollution.

    The investment strategy would provide incentives for industry to develop emission reduction technologies for use in California and abroad, thereby maintaining California’s lead in technology development. It should also leverage the talent at California’s universities to develop new technologies for reducing emissions and train the next generation of technicians that will be necessary to operate and service these technologies.

    Many California business people look forward to all the money they can make if there is a more level playing field, so that the price of fossil fuels rises to better reflect its costs.

    The sticks

    Over the last hundred years, average temperatures have increased 1.2°F, sea levels have risen by 3 to 8 inches, and spring runoff has decreased 12 percent. Over the last 50 years, observations reveal trends toward warmer winter and spring temperatures, a smaller fraction of precipitation falling as snow instead of rain, a decrease in the amount of spring snow accumulation in lower and middle elevation mountain zones, an advance in snowmelt of 5 to 30 days earlier in the spring, and a one- to two-week shift in the timing of spring flower blooms.

    CA may warm as much as 1.1°F more from greenhouse gases already emitted.

    As a result, some impacts from climate change are now unavoidable.

    For example, studies show that some unique ecosystems, such as coral reefs, and those in artic and alpine regions, have been or will be severely damaged or lost as a result of climate changes already underway. However, depending on the amount of climate change emissions emitted over the next few decades, an opportunity remains to avoid the most severe impacts that are expected with greater rises in temperature.

    The scientific community is striving to determine how vulnerable human society and the earth systems on which it depends are to future climate changes. Although no consensus has been reached as to what constitutes “dangerous” climate change, there has been increasing warning about the impacts of global average temperatures rising over 3.6°F (2°C). These include a rapid increase in global hunger, health risks, and water shortages. Temperature rises above 3.7°F (2°C) also increase the risk of abrupt climatic changes such as rapid sea level rise from the disintegration of the West Antarctic Ice Sheet.

    These worries lead to the conclusion that the UK’s goals of reducing carbon emissions by 60% by 2050, to keep atmospheric carbon levels below 550 parts per million (ppm), may not be ambitious enough. [Note: neither this report nor the UK proposals indicate that we who emit a disproportionate amount of carbon should cut back more, nor that we who are disproportionately responsible for the emissions to date should cut back more).

    What will happen to CA over the next century? Intergovernmental Panel on Climate Change has produced several scenarios – how we might behave in the future. The CA Climate Action Team looked at three of these scenarios for their high, medium and low impact futures.

    The highest emissions scenario (A1fi) represents a world of rapid fossil-fuel intensive economic growth, global population that peaks mid-century then declines, and the introduction of new and more efficient technologies toward the end of the century.

    The medium-high emissions scenario (A2) projects continuous population growth with slower economic growth and technological change than in the other scenarios. In contrast, the lowest emissions scenario (B1) characterizes a world with population growth similar to the highest emissions scenarios, but with rapid changes towards a service and information economy and with the introduction of clean and resource-efficient technologies.

    [Note: these are the high, medium, and low scenarios for this century, assuming that we don’t really try to address climate change. The B1 storyline, with a global rather than a regional approach, has some advantages and some disadvantages, but the net result is lower emissions.]

  • A diminishing Sierra snowpack of up to 90 percent during the next 100 years threatens California’s water supply and quality as the Sierra accounts for almost all of the surface water storage in the state.
  • Increasing temperatures from 8 to 10.4ºF, as expected under the higher emission scenarios, will cause a 25 to 35 percent increase in the number of days Californians are exposed to ozone pollution in most urban areas. This will offset many of the state’s efforts to reduce pollution. Temperature increases are likely to mean an increase in heat-related deaths and pestilence. Those most vulnerable are at greater risk: children, the elderly, and minority and low-income communities.
  • The agriculture industry is one of the largest industries in the state. Potential impacts from limited water storage, increasing temperatures, and salt water in the levees would threaten this industry and its economic contribution to the state. Direct threats to the structural integrity of the state’s levee system would also have immense implications for the state’s fresh water supply, food supply, and overall economic prosperity.
  • Erosion of our coastlines and sea water intrusion into the state’s delta and levee systems may result from a 4- to 33-inch rise in sea level during the next 100 years. This will further exacerbate flooding in vulnerable regions.
  • Pest infestation and increasing temperatures would make the state’s forest resources more vulnerable to fires. Forest fires not only adversely affect the state’s economy, they also cause increases in pollution damaging public health, visibility, and property.
  • Increasing temperatures will boost electricity demand, especially in the hot summer season. By 2020 this would translate to a 1 to 3 percent increase in demand resulting in potentially hundreds of millions of extra energy expenditures.
  • These impacts will affect everyone. However, in many cases the most vulnerable are children, the elderly, and the frail who suffer disproportionately when pollution increases and temperatures rise. Low-income and minority communities are also at greater risk as limited resources and current disparities in health care limit the capacity of residents in these communities to adapt and respond.

    More detail (and there is lots of detail, see the report for more):

    Temperature and Public Health

    Temperature rises significantly over the 21st century, from approximately 3ºF (1.5ºC) in the lower emissions .. and 8ºF (4.5ºC) in the medium-high emissions scenario .. to 10.4ºF (5.8ºC) in the higher-emissions scenario ..There is no clear trend in precipitation projections for California over the next century. However the consensus of the recent IPCC model projections.. is for relatively little change in total precipitation, with a tendency toward a slightly greater winter and lower spring precipitation.

    [For those wanting more information on the effects of a 1°F increase in world temperature, see Jane Kay’s excellent series on Polar Warming, Seashore Sea Change, and Survival of a Reef.]

    Climate change will affect the health of Californians due to increases in the frequency, duration, and intensity of conditions conducive to air pollution formation, oppressive heat, and wildfires. The primary concern is not change in average climate, but rather the projected increase in extreme conditions that are responsible for the most serious health consequences.

    Californians experience the worst air quality in the nation, with annual health and economic impacts estimated at 9,000 deaths and $60 billion per year. Ozone and particulate matter (PM) are the pollutants of greatest concern, and the current control programs for motor vehicles and industrial sources cost about $10 billion per year.

    Maximum ozone levels are about double the current air quality standards. Climate change will slow progress toward attainment and increase control costs by boosting emissions, accelerating chemical processes, and raising inversion temperatures during summertime stagnation episodes. The number of days meteorologically conducive to pollution formation may rise by 75 to 85 percent in the high ozone areas of Los Angeles (Riverside) and the San Joaquin Valley (Visalia) by the end of the century under a higher temperature scenario, and by 25 to 35 percent under the lower temperature path.

    In addition, global background ozone (primarily formed from methane and nitrogen oxides from fuel combustion) is projected to increase by 4 to 10 percent (low scenario) to 25 percent (high scenario) by 2100. If background ozone increases by the amount projected for the high scenario, the ozone targets would be impossible to attain in much of California, even with near-zero local emissions.

    For the high temperature scenario, the number of days higher than 90°F in Los Angeles and higher than 95°F in Sacramento will increase to about 100 days by the end of the century, almost twice the increase projected under the lower temperature path. Individuals likely to be the most affected include the elderly, already ill, and poor. On peak demand summer days in 2100, California would need at least 10 percent more electricity, compared to total generation capacity today, for air conditioning alone.

    Water Resources

    [For out-of-staters, precipitation in California does not overlap well with sunshine. Fortunately, much of the precipitation in the Sierras falls as snow, and there is a gradual release of water in late spring and early summer. This will change.]

    Although precipitation is projected to change only modestly over this century, rising temperatures are expected to lead to diminishing snow accumulation in the Sierra Nevada. Higher temperatures will mean more precipitation will fall as rain instead of snow and the snow that does fall will melt earlier in the spring. Delays in snow accumulation and earlier snowmelt will have cascading affects on water supplies, natural ecosystems, and winter recreation.

    [All scenarios show] losses of spring snow accumulation, largely over the Sierra Nevada, to become progressively larger during the 21st century. By the 2035 – 2064 period, snowpack in the Sierra Nevada could decrease 12 to 47 percent from historical levels under the lower temperature scenarios, and decrease 26 to 40 percent in the higher temperature scenarios. Precipitation changes will play a partial role in the reductions for the lower temperature cases. By the end of century, snowpack could decrease by as much as 90 percent in the higher temperature scenarios, almost double the losses expected under the lower temperature scenarios.

    Declining snowpack will aggravate the already overstretched water resources in California. The snowpack in the Sierra Nevada provides natural water storage equal to about half the storage capacity in California’s major man-made reservoirs. The snowpack holds the winter precipitation in the form of snow and releases it in the spring and early summer as the snow melts. This loss in storage could mean more water shortages in the future. However, the full effect of this storage loss will depend in part on whether reservoirs can be managed to capture the earlier snowmelt while loosing flood control capacity.


    Agriculture, along with forestry, is the sector of the California economy that is most likely to be affected by a change in climate. California agriculture is a $68 billion industry. California is the largest agricultural producer in the nation and accounts for 13 percent of all U.S. agricultural sales, including half of the nation’s total fruits and vegetable. The agriculture sector is likely to bear a disproportionate share of any water scarcity due to any reduced water availability from climate change.

    Possible effects of excessively high temperature include decreased fruit size and quality for stone fruits, premature ripening and possible quality reduction for grapes, reduced fruit yield for tomatoes, increased incidence of tip burn for lettuce, and similar forms of burn for other crops.

    The medium-high and low-emissions scenarios produce changes by the end of this century, wherein the local winter climate approaches critical chill hour thresholds for many species of fruit trees. (Chill hour is the number of hours below a critical temperature.)

    [One person on the SF peninsula told me that his apple trees are bearing less, which he attributes to fewer chill hours.] Additionally, pests look to be an increasing problem for agriculture.

    Sea Level

    Sea level rise, superimposed on predicted tides, weather variations, and El Nino fluctuations, is projected to rise from 4 to 33 inches during the 2000 to 2100 period. This compares to a rate of approximately 7.6 inches (19 cm) per century observed during the last 100 years. On the open coast, impacts during these events will continue to be exacerbated by high surf from wind, waves, and, in the Sacramento/San Joaquin Delta of the San Francisco Bay estuary, by floods that may further jeopardize levees and other structures.

    [The assumptions about sea level increases are changing, see Melting Ice.]

    Forests and Natural Landscapes

    The distribution of species is expected to shift, the risk of climate-related disturbance such as wildfires, disease, and drought is expected to rise, and forest productivity is projected to increase or decrease depending on species and region. The ecosystems most susceptible to temperature rise are the alpine and sub-alpine forest cover. In addition, changes in fire frequency are expected to contribute to the increase of grasslands, largely at the expense of woodland and shrub-land ecosystems.

    [Excluding the effects of increased bouts of extreme weather], projections suggest that the risk of large wildfires statewide may rise almost 35 percent by mid-century and 55 percent by the end of the century under a medium-high emissions scenario, almost twice that expected under lower emissions scenarios.

    These increases in fire season severity could lead to more bad air days and increased damage costs of approximately 30 percent above current annual damage costs.

    Although society has developed a number of ways to adapt to wildfires, climate change, along with the multiplying impacts of other stresses such as population growth and land-use change, may be pushing California outside of its coping range.

    [Expanded range for pests such as pine pitch canker] could result in increased disease severity and economic loss.

    [Earlier projections were more optimistic about increased growth in forests.] The most recent assessment of the impact of climate change on the California forest sector used an industry standard planning tool to forecast 30-year tree growth and timber yields for forest stands in El Dorado County under a high and medium temperature scenario.

    Conifer tree growth was reduced under all downscaled climate change scenarios. In the medium temperature scenario, productivity in mature stands was reduced by 20 percent by the end of the century. The reductions in yield were more severe (30 percent) for pine plantations. Projections further indicate that the reduced growth rates could lead to substantial decrease in tree survival rates.

    Electricity Sector

    Changes in precipitation levels, should they occur, and patterns and timing of snowmelt would alter the amount of electricity that hydroelectric facilities could generate. It would also affect seasonal availability, with less water available for hydroelectric generation in the late spring and summer months when demand is the highest.

    Currently, hydropower generation contributes about 15 percent of the in-state electricity production, with a range from 9 to 30 percent due to variations in climatic conditions… The most recent study using an economic-engineering optimization model of the state water system suggests that under a medium temperature scenario, annual generation by the end of this century is expected to decrease by about 30 percent and stream flows are expected to decrease by 28 percent.

    It is important to emphasize that even relatively small changes in in-state hydropower generation result in substantial extra expenditures for energy generation, because losses in this “free” generation must be purchased from other sources.

    For example, assuming a decrease of 10 percent from the current average instate generation level from this renewable energy source, and assuming a price of about 10 cents per kilowatt-hour, this decrease would result in an additional $0.35 billion per year in net expenditures to purchase sufficient electricity to replace the electricity that otherwise would be generated using hydroelectric resources.

    Electricity demand is projected to rise between 3 to 20 percent by the end of this century. These results are based on correlation functions relating electricity demand with temperatures in key areas in California and future climate projections assuming current socio-economic conditions. In the next 20 years electricity demand would increase from 1 to 3 percent from the baseline, and peak electricity demand would increase at a faster rate.

    Since annual expenditures of electricity demand in California represent about $28 billion, even the relatively small increases in energy demand would result in substantial extra energy expenditures for energy services in the state. For example, assuming a linear increase in electricity expenditures from the historical period, a 3 percent increase in electricity demand by 2020 would translate to about $1.2 billion a year in extra electricity expenditures.

    All of this will be very costly, both in the short and long run. Next post (I hope) –technological changes that can make a difference.

    2 Responses to “California’s Climate Change Plan – the Why”

    1. CA seems to be the pilot state in this. PA isn’t in the mood politically, while NJ probably is. I’l do some Googling to find out and get back to you. Any suggestions?

      Grant Stevenson
      Bethlehem, e,-c. PA

    2. […] Still no time to get to blogging the post I had planned, so instead I’ll direct you to Karen Street’s post on California’s climate change plan. And all her other climate change posts. […]