As President Barack Obama prepares to deliver his State of the Union address, we believe it’s a good time to take a look at the state of our climate: the growing impacts of climate change, recent progress in reducing U.S. emissions, and further steps we can take to protect the climate and ourselves.
The consequences of rising emissions are serious. The U.S. average temperature has increased by about 1.5°F since 1895 with 80 percent of this increase occurring since 1980, according to the draft National Climate Assessment. Greenhouse gases could raise temperatures 2° to 4°F in most areas of the United States over the next few decades, bringing significant changes to local climates and ecosystems.
With the Intergovernmental Panel on Climate Change (IPCC) poised to release its Fifth Assessment of the science underpinning our understanding of climate change, it’s useful to take a step back and recap some of the “big picture” facts.
What is already clear from the science:
- Carbon dioxide and other greenhouse gases act to warm the planet.
- Carbon dioxide is accumulating in the atmosphere due to emissions from human activities.
- The Earth has been warming during the past century. The amount and speed of the warming is unusual compared to past records.
- Humans’ emissions of greenhouse gases are largely responsible for this warming.
- If emission rates continue, the warming in the 21st century will be much more significant than the warming in the previous century.