We’re falling short on efforts to stop global warming. Here’s how we can get on track.

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It’ll be even harder than we thought.

Three years after representatives of almost 200 nations met in Paris to agree on a set of goals to curb global warming, a U.N. climate advisory group has issued a stark new report indicating that meeting those goals may be much more difficult than previously recognized.

The report, issued on Monday by the Intergovernmental Panel on Climate Change (IPCC), shows that “we are nowhere near on track to meet the goals of the Paris Agreement,” said Rachel Licker, a senior climate scientist with the Union of Concerned Scientists, a Cambridge, Massachusetts-based science advocacy nonprofit. “Current commitments have us on track to reach a level of global warming that is closer to 3 degrees Celsius (C) — far above the 1.5 C and 2 C targets of the Paris agreement.”

Image: Rachel Licker
Dr. Rachel Licker, a senior climate scientist with the Climate & Energy Program at the Union of Concerned Scientists.Courtesy Union of Concerned Scientists

A couple of degrees might not sound like much. But Licker said it could bring devastating changes in the global environment, including large increases in sea levels and the loss of the world’s coral reefs.

Why is it so hard to stop climate change? Can we turn the tide? What is required of governmental leaders — and how can citizens help? Licker answered these and other questions in a wide-ranging interview with NBC News MACH. The interview, conducted via internet chat and email, has been edited for clarity and brevity.

NBC News MACH: We’ve known for years that climate change poses major threats to the planet. Why the new report — and why now?

Licker: The report was requested by members of the U.N. Framework Convention on Climate Change, including the U.S., during the adoption of the Paris Agreement. Member countries recognized that the commitments countries were putting forth at that point were not enough to meet the Paris Agreement goals, so they asked the IPCC to provide them with technical information that could inform their deliberations. The report will serve as key technical input for a discussion at the next U.N. climate change conference in Poland later this year.

And the report makes it clear that we must do more to limit the rise in global temperatures?

That’s correct. The report brings greater clarity to the actions necessary to limit global warming to 1.5 or 2 degrees Celsius (2.7 degrees or 3.6 degrees Fahrenheit). It shows society will need to achieve net-zero emissions of carbon dioxide by 2050, and achieve net reductions of other global warming gases by 2030.

One IPCC scientist said the effects of climate change could be irreversible. You’ve mentioned sea level rise and the loss of coral reefs as possibilities. Can you explain just what’s at stake here?

Coral reefs are critical for a variety of reasons. They are home to huge concentrations of marine biodiversity and, as such, are important sources of food as well as tourism revenue. They also provide important services to coastal communities. For example, they help break up storm waters before they make landfall.

Earth’s sea level has already risen by about seven or eight inches since 1900. The new report shows that in a 2 C world, sea level rise is projected to be about four inches higher than it would be in a 1.5 C world. That’s enough to expose an additional 10 million people around the world to risks from sea level rise.