The world can still meet one of the two international goals for limiting warming if nations do all they can to fight climate change. A new study shows that the planet is blowing past a threshold that scientists say will protect Earth more.
The goal of keeping global warming at 2 degrees Celsius (3.6 degrees Fahrenheit) hotter than pre-industrial times is no longer out of reach, according to a study published Wednesday in the journal Nature.
The study says that if countries fulfill their pledges to curb carbon emissions, then they will be able to reach net zero carbon emissions by mid-century.
This 2 degree warmer world still represents what scientists say is a profoundly disrupted climate with fiercer storms, higher seas, animal and plant extinctions, disappearing coral, melting ice and more people dying from heat, smog and infectious disease. It is not the goal that world leaders say they want. Unless dramatic new emission cuts are promised and achieved this decade and within the next three years, the world will blast past that more prominent and promoted goal.
The goals of 1.5 degrees and 2 degrees are part of the Paris climate pact. The goal was set years ago.
For the first time, we can keep warming below the symbolic 2-degree mark with the promises on the table. That assumes that the countries follow through on their promises, according to the study lead author.
Climate scientists and the authors say that is a big if. Political leaders are actually doing what they promise.
The study only looked at the optimistic scenario. It does not check whether governments are making efforts to implement their long-term targets and whether they are credible, according to a New Climate Institute scientist who analyzes pledges for Climate Action Tracker.
Hohne's team and others who track pledges have found that limiting warming to 2 degrees is still possible. The difference is that the study was peer-reviewed and published in a scientific journal.
The 2-degree world requires countries to fulfill their promises. Some countries will exceed their promised carbon emissions cuts because of cheaper wind and solar. He said that it is not unreasonable to take countries at their word when it comes to climate action.
He said that limiting warming to 2 degrees is still a big improvement over the past five or ten years, when everyone laughed and said we would never see targets on the table that would bring us closer to 2 degrees. I think it's important for countries to see optimism. There is hope.
About 20% to 30% of that hope is due to the Paris climate agreement, but the rest is due to earlier investments by countries that made green energy technologies cheaper than dirty fossil fuels.
He said that even if that is good news, it is not all good.
Neither do we have a margin of error, nor do the pledges put us on a path close to 1.5 degrees.
The United Nations scientific expert team studied the differences between the 2- and 1.5-degree thresholds and found that the damages to Earth were worse at 2 degrees of warming. The world has recently tried to make the 1.5 degrees goal a reality.
Earth has already warmed at least 1.1 degrees Celsius (2 degrees Fahrenheit) since pre-industrial times, so 2 degrees of warming really means another 0.9 degrees Celsius (1.6 degrees Fahrenheit) hotter than now.
Glen Peters, a climate scientist who tracks emissions with the Global Carbon Project, said that the analysis looks good and solid, but there are always assumptions that could be important.
According to Peters, the biggest assumption is that nations will get to net zero carbon emissions by the year 2050.
He said that making pledges for 2050 is cheap and that backing them up with necessary short-term action is hard.
More information: Malte Meinshausen et al, Realization of Paris Agreement pledges may limit warming just below 2 °C, Nature (2022). DOI: 10.1038/s41586-022-04553-zNet-zero commitments could limit warming to below 2 degrees C. There is a DOI: 10.1038/d41586-022-00874-1.
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