To keep global warming under 1.5°C, countries need to increase their efforts five-fold. That means phasing out fossil fuels and increasing renewable energy. 

Trucks pass a wind farm in California. Globally, transportation is a major greenhouse gas emitter. Credit: David McNew/Getty Images
Trucks pass a wind farm in California. Globally, transportation is a major greenhouse gas emitter. Credit: David McNew/Getty Images
The gap between the goals of the Paris climate agreement and what countries have committed to do to achieve them is widening, a new United Nations report warns, posing a significant challenge to political leaders as they head into international climate negotiations next week.
Without a rapid reshaping of the global economy and energy systems—including ending the using of coal and ramping up renewable energy—the world is on track to sail past the temperature targets of the Paris Agreement. That could lock in centuries of dangerous warming.
Global greenhouse gas emissions rose about 1 percent last year, but the biggest change comes from dimming hopes for the rapid expansion of technology to capture carbon from the air and store it underground.
Previous UN studies had assumed carbon capture technologies would be widely deployed later in the century, allowing more leeway for global emissions. Instead, the latest Emissions Gap Report, published Tuesday, revised downward the world's carbon budget—the total emissions allowable to stay within the targets of the Paris Agreement.
"The science is clear," UN Environment Program Acting Executive Director Joyce Msuya said in a statement. "For all the ambitious climate action we've seen—governments need to move faster and with greater urgency."
Despite significant success in recent years in reining in emissions, nations must effectively triple their pollution-cutting goals if the world hopes to hold warming below 2 degrees Celsius (3.6°F) compared to pre-industrial times, the report says. To keep global warming to 1.5°C (2.7°F), countries will have to boost their ambition by a factor of five.

Global Emissions Likely Need to Peak by 2020

The annual report, issued by the UN Environment Program, provides the definitive accounting of national pledges to cut emissions as part of the Paris Agreement and compares them to the latest climate science.
This new accounting finds that that gap is significant.
Global emissions will likely need to peak by 2020 and fall 25 percent below current levels by 2030 to limit warming to below 2°C. Keeping warming to 1.5°C will require a cut of 55 percent. Under current policies, however, emissions are set to keep rising through 2030. And even if all nations keep their Paris pledges, emissions are projected to be about the same in 2030 as they are today.
The Global Emissions Gap Between Policies and the Paris Goals
The report comes at the end of a year that's seen a record-setting heat wave cover much of the globe, devastating hurricanes hit North America and Asia and the most lethal and destructive wildfire in California's history. It also comes on the heels of an earlier report from the UN and one released by the U.S. government last week that underscore the risks of failing to limit greenhouse gas emissions to slow climate change.
"The urgency of this message is getting louder and louder for the everyday public, and the climate impacts are definitely outpacing our response," said Kelly Levin, a lead author of the report and a senior associate at the World Resources Institute. "This gap in action is contributing to many of the impacts we're seeing around the world."
Many of the world's leading economies, including the United States and the European Union, are failing to meet the pledges they made under the Paris Agreement, the report says.
Much of the new research that this year's Gap Report drew on was associated with a UN report, published last month, examining what it would take to limit warming to 1.5°C and the costs of failing to do so. It found that the window to meet the goal is rapidly closing, and that failing to do so would lead to damaging impacts in many regions of the world.

How Can Countries Get on Track to Meet the Paris Goals?

The new report highlights a range of policies that can help keep emissions in check.
Most G20 nations can take actions to end their fossil fuel subsidies, phase out coal-fired power plants, implement policies to boost industrial efficiency and increase support for the use of renewable energy to heat and cool buildings.
Norway has adopted a combination of incentives that helped electric vehicles grab nearly 40 percent of the new car market there last year. A few countries have adopted efficiency standards for heavy-duty vehicles, but the others have yet to do so.
Broadly speaking, the largest potential for emissions cuts lies in three areas, the report says: 
  • boosting wind and solar power, 
  • improving efficiency of household appliances and cars,
  • and stopping deforestation while allowing new forests to grow.
The report also says carbon prices offer tremendous room for improvement. About half the world's emissions do not carry any price or tax. The report cites various studies to say that adopting a carbon tax of $70 per ton could, along with other policies, lead to emissions cuts of up to 40 percent in some countries.

What About Cities and States That Are 'Still In'?

The report also highlights the role of local and regional governments and the private sector. In the U.S., several states have recently adopted more ambitious renewable energy targets, for example. These local efforts can help build political support for larger national policies, the report says, and serve as testing grounds.
More than 7,000 cities and 6,000 companies have committed to cut emissions. But when you add up the pledges, and take out overlaps between them and national actions, the direct emissions cuts are modest.
"I was expecting the contributions to be much greater," said Angel Hsu, an assistant professor at Yale-NUS College and the lead author of the chapter on local and private action.
She said tracking whether all these entities are meeting their pledges is difficult. But she added they have the potential to lead to much larger emissions reductions.
The most important takeaway from the report may be the simplest: even if all the world's governments were to meet their most ambitious pledges made so far to cut emissions, they would fall far short of the larger goals of limiting warming. Sooner or later, net emissions from the use of fossil fuels must hit zero for warming to end.
"Now more than ever," the report says, "unprecedented and urgent action is required by all nations."