I recently wrote about how partisan fights on Capitol Hill are distracting lawmakers from taking meaningful action to address climate change. Even if the policymakers in the United States drag their feet, the world is moving forward, spurred by the latest assessment of the status of global climate change.
Last week, the Intergovernmental Panel on Climate Change, which is made up of the world’s leading climate scientists, released a summary of the first part of its fifth assessment report. The panel concluded that climate change is happening; scientists are 95% certain that humans are causing it; and dramatic steps will be needed to reduce the impacts of climate change.
United Nations Secretary General Ban Ki-Moon said in a video address that he plans to convene a climate summit in September 2014 in an effort to build momentum going into the 21st session of the United Nations Framework Convention on Climate Change Conference of the Parties scheduled for December 2015. He said that the IPCC’s fifth assessment will be essential as governments work to finalize legal agreements to address climate change.
The IPCC boiled its findings down into several “headlines.” Below are a few of the key highlights:
- Warming of the climate system is unequivocal.
- Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.
- It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.
- Atmospheric concentrations of carbon dioxide, methane, and nitrous oxide have increased to unprecedented levels not seen in the last 800,000 years.
- Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system.
- Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.
- Most aspects of climate change will persist for many centuries even if emissions of CO2 are stopped. This represents a substantial multi-century climate change commitment created by past, present, and future emissions of CO2.
The remaining parts of the fifth assessment report are scheduled to be released in 2014.
As the UN Secretary General said last week, “The heat is on. Now we must act.”