As global leaders kick off the latest round of the UN Climate Summit in Paris, talk is suddenly filled with a swirl of data, studies and projections. And it all can get pretty confusing.
So we're highlighting just three numbers that may help to understand what scientists say is going on and what can be done about it:
- 2 degrees Celsius. That's the number that UN scientists say is the upper limit for global temperatures to rise, compared to pre-industrial levels, before hitting the most disruptive consequences of climate change. For context, since around the start of the Industrial Revolution around 1880, global temperature has risen less than 1 degree (.86) Celsius. In 2009, countries, including the U.S., signed on to a deal in Copenhagen agreeing to take action to avert more global warming, citing the 2 degree number, but how countries will get there is still a big question. And some, including representatives from low-lying island nations, have criticized the 2 degree mark as too high.
- 80 percent of the world's energy still comes from fossil fuels. That's according to the Institute for Energy Research. A key issue in Paris will be how large, developing nations – such as China, India and Brazil – will power their economies. A World Bank report out this year found that poor communities tend to live in more vulnerable areas when it comes to climate change, and extreme climate events could increase wealth inequality in the future. India, for example, pledged to have 40 percent of its energy come from renewable sources by 2030, but still relies heavily on coal to bring electricity to millions of its residents. Where will the world's future energy come from and what role will renewables play?
- 2017 is the year the world economies have to turn the tide on carbon emissions. So said the chief economist for the International Energy Agency back in 2011. The agency also predicts that the world's demand for energy is going to grow by nearly a third (between 2013 and 2040). The Intergovernmental Panel on Climate Change says timely action will require "an urgent and fundamental departure from business as usual." President Barack Obama added further urgency this week, when he told leaders at the Paris talks that it was nearly too late for action and that "when it comes to climate change, that hour is almost upon us.”