- With only a single degree Celsius of warming so far, the world has seen a crescendo of deadly wildfires, heatwaves and hurricanes.
- Temperatures are on track to rise roughly 4C by the century's end, a scenario that would tear at the fabric of civilisation, scientists say.
- To cap global warming at two degrees Celsius.
Humanity is falling further behind in the race against climate change, with the gap between greenhouse gas emissions and levels needed to achieve the Paris climate treaty temperature goals continuing to widen, the UN said Tuesday.
With only a single degree Celsius of warming so far, the world has seen a crescendo of deadly wildfires, heatwaves and hurricanes.
On current trends, temperatures are on track to rise roughly 4C by the century's end, a scenario that would tear at the fabric of civilisation, scientists say.
To cap global warming at two degrees Celsius (3.6 degrees Fahrenheit), national carbon-cutting pledges annexed to the 2015 Paris Agreement must collectively triple by 2030, according to the UN Environment Programme's (UNEP) Emissions Gap report.
To hold the rise in Earth's temperature to 1.5C above the preindustrial benchmark, such efforts would have to increase fivefold.
"The emissions gap is much bigger than last year," UNEP's Philip Drost, one of several coordinators for the annual report's ninth edition, told AFP.
One obvious reason was a spike last year in the quantity of carbon dioxide, methane and other planet-warming gases escaping into the atmosphere.
This trend is set to continue in 2018, which saw a jump in CO2 emissions from the energy sector, according to the International Energy Agency, as well as an increase in the atmospheric concentration of CO2.
But the gap between where we are and where we need to be also grew on paper: new calculations by the UN's top science panel sharply reduce the real-world potential for drawing CO2 out of the air, whether by planting more trees or capturing and storing CO2 emitted by power plants.
More broadly, the Intergovernmental Panel on Climate Change (IPCC) special report released last month concluded that 2C of warming -- once seen as a safety guardrail -- would in fact usher in a maelstrom of deadly extreme weather.
Taken together, rising emissions and revised projections on CO2 removal have widened the emissions gap by 15 percent for a 2C world, and by nearly 70 percent for the 1.5C target, according to the new report.
The news comes despite breakneck growth in solar and wind power, gains in energy efficiency, and climate action by business and local governments, said Andrew Steer, president and CEO of the Washington DC-based World Resources Institute.
"We are chasing a bus" -- climate change -- "and we are going faster and faster, setting new world records," he said by phone.