The last few weeks have demonstrated an unfortunate juxtaposition between the U.S. federal climate policy debate and the scientific case for climate action. Strong evidence for the need to regulate greenhouse gas emissions continues to pile up, but meanwhile last week the U.S. House Appropriations Committee passed drastic cuts to environmental regulations in the Fiscal Year 2012 Interior and Environment Appropriations Bill.
The bill proposes $1.5 billion in cuts from the Environmental Protection Agency (EPA)’s budget. Members of Congress supporting these cuts hold that the EPA is too costly and hampers economic growth. The bill would cut climate change spending by $83 million, or 22 percent below last year’s budget. One of the many prohibitions in the bill prevents the EPA from regulating stationary greenhouse gas emissions. EPA’s regulation of climate-altering greenhouse gases (GHGs) under the Clean Air Act, which will be finalized in 2012, are the only federal greenhouse gas regulations on the table, as the U.S. has not passed comprehensive climate legislation, and the prospects for doing so in the near future seem dim. Negotiations on the House and Senate floor will likely alter the contents of the bill with a Democratic majority in the Senate that is very likely to refuse to withdraw EPA’s authority to regulate GHGs and impose major cuts on its budget. Also, President Obama threatened to veto the bill. Still, the proposed cuts highlight the strong disconnect between climate science and climate policy within the United States.
This comes at a time when the United States is suffering from a taste of the extreme weather events that unchecked climate change could make all too frequent in coming decades. Much of the U.S. is currently experiencing dangerously high temperatures and humidity levels. Temperatures in the 90s and 100s, with heat indices up to 115°, are currently plaguing most of the Midwestern U.S. and are moving eastward toward the mid-Atlantic region. Here in Washington, D.C., home of the Worldwatch Institute’s headquarters, we experienced temperatures around 100° with dangerous heat indices around 110° for several days in a row. Nearly 1000 high temperature records have been broken this July, according to the National Oceanic and Atmospheric Administration (NOAA).
High temperatures are not unique to 2011. NOAA’s new climate “normals”, 30-year climate averages calculated from data collected across the U.S., show that 1981-2010 was 0.5 degrees Fahrenheit (.28 C) warmer than the 1971-2000 average. The annual “normal” minimum and maximum temperature rose for all of the lower 48 states. The figure to the right shows the change in climate normals from 1971-2000 to 1981-2010, demonstrating warming across the board, but particularly in the Southwest and around the Great Lakes.
Aside from record temperatures, July has also seen widespread flooding, severe drought and massive forest fires. To help manage flooding, the House nearly unanimously approved a bill to overhaul flood insurance. While this bill may help victims adapt to the effects of a changing climate, it demonstrates the disconnect between the debates over managing the causes of climate change and its symptoms. Critics of the bill also note that overhauling flood insurance may further encourage development in flood prone regions.
In order to scientifically link these extreme events to climate change it is necessary to look at attribution data, which can probabilistically attribute weather events to anthropogenic forcings by modeling scenarios with natural and anthropogenic emissions and scenarios with only natural emissions. In these studies the question isn’t whether a particular event was caused by climate change (which can never be answered with certainty) but rather how much human activities have increased the likelihood of an event of that type. The journal Nature published several of these studies earlier this year. One demonstrated that human-induced GHG emissions increased the risk for flooding in record-breaking floods in the UK in 2000 by more than 90 percent in the majority of seasonal-forecast simulations. Another study, using both observations and models, identified that human-emitted greenhouse gases were responsible for an increase in extreme rain events on more than two-thirds of data-covered North American landmasses during the later part of the 20th century. Yet another attribution study finds with 90 percent confidence that human influences have at least doubled the likelihood of a heat wave of the magnitude of Europe’s 2003 wave, which is estimated to have killed 35,000 people.
In addition to the manifestation of climate change in extreme events, it is further weakening the Earth’s mechanisms to limit the greenhouse effect. Oceans absorb close to one third of the CO2 we emit. This uptake mechanism is a vital part of the global carbon cycle and removes a large portion of anthropogenic (as well as natural) greenhouse gases from the atmosphere. Recent evidence, based on climate modeling, has been mounting, however, that the capacity of this sink is diminishing. A study published earlier this month, which employs both observational data and numerical models covering 87 percent of the North Atlantic, in order to determine the effect of increasing temperatures on the oceanic carbon sink revealed a diminishing trend in sink capacity in the ocean attributable to increasing temperature. The slowing of oceanic carbon sequestration creates a positive feedback loop. More carbon dioxide in the atmosphere further contributes to the greenhouse effect, which in turn further warms the ocean and thus further reduces oceanic carbon sequestration.
The heat waves, droughts, and floods that have plagued the U.S. over the past weeks and months are an indication of the kind of extreme weather that climate change will make more frequent. Informed policymaking in the future will hopefully engage with the scientific community to bridge the current divide between the knowledge that we need to act, and the prevailing non-action. Perhaps the current inhabitability of Washington D.C. – after all also the home of the U.S. Congress – will make our Representatives eventually sweat over how to solve this giant crisis.