Paris pledges can ward off severe warming

Accordting to a new study, pledges made in the lead-up to next week's major Paris climate change conference can avert severe climate change, but only if the words are turned into long-term action.

More than 190 countries are meeting in Paris next week to create a durable framework for addressing climate change and to implement a process to reduce greenhouse gases over time. A key part of this agreement would be the pledges made by individual countries to reduce their emissions.

The study shows that if implemented and followed by measures of equal or greater ambition, the Paris pledges have the potential to reduce the probability of the highest levels of warming, and increase the probability of limiting global warming to 2 degrees Celsius.

In the lead up to the Paris meetings, countries have announced the contributions that they are willing to make to combat global climate change, based on their own national circumstances. These Intended Nationally Determined Contributions, or INDCs, take many different forms and extend through 2025 or 2030.

Examples of these commitments include the United States' vow to reduce emissions in 2025 by 26-28 percent of 2005 levels and China's pledge to peak emissions by 2030 and increase its share of non-fossil fuels in primary energy consumption to around 20 percent. In the study, the scientists tallied up these INDCs and simulated the range of temperature outcomes the resulting emissions would bring in 2100 under different assumptions about possible emissions reductions beyond 2030.

Lead author Allen Fawcett of the U.S. Environmental Protection Agency said that they analyzed not only what the commitments would achieve over the next ten to fifteen years, but also how they might lay a foundation for the future.

The study is published in Science.