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.