Scientists have discovered that new climate models show that carbon dioxide is a more potent greenhouse gas than previously understood, meaning that the Paris agreement goals for containing global warming might be out of reach.
As shown in reviews by separate teams in half-a-dozen countries, the models which will underpin revised UN temperature projections in 2020 suggest scientists have for decades consistently underestimated the warming potential of CO2.
The United Nations Environment Programme (UNEP) also published a report which supports the scientist claims that unless the world begins to reduce greenhouse gas emissions rapidly, the Paris agreement goal will slip out of reach.
The published annual report provides a “bleak” assessment of the ever-growing gap between actual emission reduction commitments by countries and those necessary to achieve the Paris Agreement goals to limit warming to well below 2C above preindustrial levels” and pursue efforts to limit the temperature increase to 1.5C.
According to the report, global CO2 emissions have increased by around 11 percent since the last UNEP emissions gap report.
Each year of growing global emissions means that more in-depth and faster cuts are needed to meet the Paris Agreement goals and increases the amount of CO2 that would need to be removed from the atmosphere through harmful emissions to make the 1.5C target viable.
The most influential projections from government-backed teams in the US, Britain, France, and Canada point to a future in which CO2 concentrations that have long been equated with a 3C world would more likely heat the planet’s surface by four or five degrees.
Paris agreement goals running out of time
While global carbon emissions growth is still a course for concern, the persistent rise is a warning that governments aren’t doing enough to slow down the ever-growing effect of climate change.
Carbon-dioxide emissions from burning fossil fuels likely increased by 0.6 percent in 2019, down from 2.1 percent in 2018, according to a report from the Australia-based Global Carbon Project. Declines in the US and Europe were offset by increases in the fast-growing economies of China and India.
Notably, current climate and energy policies are not enough to reverse the trends in global emissions. The Paris agreement goals must be taken more seriously, and continued support for low-carbon technologies need to be combined with policies directed at phasing out the use of fossil fuels to be upheld.
The Paris agreement goals combine about 200 United Nations-organized climate change countries, aimed at limiting fossil fuel pollution, and as a global protest movement calling for tougher action on climate change gathers momentum.
The global climate outlook is “bleak,” and the planet’s pathway back to a safe climate is narrowing, the UN warned last week. The increasingly dire estimates about the pace of climate change are leading to calls for more extreme solutions than the actions that nations have already committed to.
A little positive news
While the UNEP report makes it clear that emissions are far from on track to meet the Paris agreement goals, it does contain some positive news. The climate policies enacted by countries and the falling price of clean energy technologies have made some of the worst-case emissions outcomes considerably less likely, it says.
The UNEP report projects that current policies will move emissions substantially lower than most of the Intergovernmental Panel on Climate Change (IPCC) scenarios examining potential outcomes in the absence of any action to tackle climate change, so-called “no-policy baseline” pathways.
It puts emissions in 2030 at 60GtCO2e, somewhere between SSP2-4.5 (57GtCO2e) and SSP3-6.0 (62GtCO2e), but well below SSP3-7.0 (69GtCO2e) and the worst-case SSP5-8.5 (71GtCO2e).
This follows similar estimates from the 2019 IEA World Energy Outlook, which suggested that stated plans and policies would lead to emissions lower than most IPCC baseline no-policy scenarios over the next few decades.