Climate change: UN warns world is on track for catastrophic warming of 2.7°C

"The heat is on" is the title of the new Emissions Gap Report published on Tuesday by the United Nations Environment Program (UNEP). The report analyzes the updated national climate plans — known as nationally determined contributions (NDCs) — of 120 countries.

The NDCs are at the core of the Paris Climate Agreement. All signatories are required to set national climate targets and regularly report on both their implementation and new targets.

The name of the UNEP's latest report says it all — and its findings are sobering. With the updated NDCs, greenhouse gas emissions will only see a reduction of 7.5% by 2030. But in order to achieve the goal of the Paris Agreement and limit global warming to 1.5 degrees Celsius/2.7 degrees Fahrenheit (compared to 1900 levels), greenhouse gases would have to fall by 55%.

'The clock is ticking loudly'

In other words, the world must cut its emissions by 28 gigatons of CO2 equivalent (GtCO2e) per year by 2030. To limit emissions to 2 C, countries would still have to reduce their climate-damaging emissions by 30%, or 13 GtCO2e.

"To be clear: we have eight years to make the plans, put in place the policies, implement them and ultimately deliver the cuts. The clock is ticking loudly," Inger Andersen, executive director of the UNEP, wrote in the report.

If, however, countries just stick to their own national climate targets, which they are allowed to set individually under the Paris Agreement, the world is on track for a temperature rise of 2.7 C.

"That would result in catastrophic climate change that we would not be able to cope with at all — that must be avoided at all costs," said Niklas Höhne, director of the Cologne-based nonprofit research organization New Climate Institute and professor of climate protection at Wageningen University in the Netherlands.

Pandemic was a missed opportunity

The UNEP report expressed disappointment that investments designed to stimulate the economy after the coronavirus pandemic had barely taken climate protection into consideration. According to the report, less than one-fifth of recovery packages are likely to contribute to a reduction in greenhouse gas emissions.  

In 2020, the COVID-19 pandemic led to a 5.4% drop in new emissions worldwide. At the same time, the concentration of greenhouse gases in the atmosphere reached a new high, according to a report from the World Meteorological Organization, the UN's weather and climate agency. 

Compared to the previous year, the increase was even higher than the average rise over the past decade, the report said. Or, as the UNEP puts it: "CO2 concentrations are higher than at any time in the last 2 million years."

Net-zero targets bring hope

According to the UNEP, the net-zero pledges made by a host of countries, including the United States, Japan, China, as well as the European Union, could make a significant difference.

Net zero means that for all of the greenhouse gas emissions caused by humans, the same amount must be removed from the atmosphere. Artificial and natural greenhouse gas sinks, such as peatlands or forests, can be offset against greenhouse gases emitted.

"If made robust and implemented fully, net-zero targets could shave an extra 0.5 C off global warming, bringing the predicted temperature rise down to 2.2 C," the UNEP report says. It is critical, however, of the fact that many countries are not planning to start working toward net-zero until after 2030.

An extreme world — even with a 2 C increase

Countries need to link long-term net-zero targets to their ongoing NDCs and move forward quickly, UNEP Executive Director Andersen urged in the report's foreword. "This can't happen in five years. Or in three years. This needs to start happening now," she said.  

Even if global warming were stopped at 2 C, Niklas Höhne of the New Climate Institute said the world would be a changed place. "We are currently at a temperature increase of 1 C. And we're seeing droughts, forest dying, floods — like in [Germany's] Ahr Valley — and fires all over the world. An increase of 2 C means, as a first approximation, twice as many floods, twice as many extreme weather events."  

Potential in methane, carbon markets

The UNEP report sees another opportunity to close the gap between climate targets and the current reality, through the reduction of methane emissions.

Methane not only escapes during the extraction of fossil fuels, but is produced during the decomposition of organic waste, in the treatment of wastewater and through livestock farming and rice cultivation.  

Though methane only lingers in the atmosphere for 12 years compared to up to centuries for CO2, it is much more potent and therefore significantly more harmful to the climate during its relatively short lifespan. As such, a rapid reduction of methane emissions could limit temperature rise faster in the short term than a drop in CO2, according to the report.

Mechanisms such as compensation payments to poorer countries or clearly defined and properly designed carbon markets could also lead to countries taking more ambitious climate protection measures, the UNEP authors wrote. 

"We are so late to climate action that it is imperative that developed countries, in addition to efforts at home, help developing countries reduce emissions as quickly as possible. The emissions gap is so large that no country can sit back," Höhne said.

This year's Emissions Gap Report highlights not only failures but also the enormous potential for more climate action, wrote UNEP's Andersen. For example, policies implemented between 2010 and 2021 will lower annual emissions by 11 GtCO2e in 2030 compared to what would have happened without them.

Though she said "we should not despair," she also called on the world to "wake up to the imminent peril we face as a species. We need to go firm. We need to go fast. And we need to start doing it now."