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Gases that trap heat in the atmosphere, greenhouse gases (GHGs) absorb and emit radiant energy within the thermal infrared range, causing what is known as a “greenhouse effect.” The culprits include—but aren’t limited to—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and fluorinated gases like hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride and nitrogen trifluoride.
The amount of CO2 emissions associated with all the activities of a person or other entity, carbon footprints tend to get a lot of attention, but there’s more to environmental sustainability than just CO2 reduction. And, each gas’s effect on climate change depends on the concentration or abundance of the gas; how long it stays in the atmosphere; and how strongly it impacts the atmosphere. Some gases are more effective than others at making the planet warmer and “thickening the Earth's blanket,” the EPA points out.
Knowing this, many entities (e.g., countries, regions, cities and individual organizations) around the world have made net-zero commitments. Fundamentally, net-zero means that a company (or state, or country) has reached a point where it doesn’t put any more carbon into the atmosphere than it takes out. According to the United Nations, to keep global warming below 1.5°C, emissions have to be cut by at least 45% by 2030.
If a new report is on target, there’s still quite a way to go before the world achieves its net-zero commitments. According to the UN Environment Programme’s (UNEP) Emissions Gap Report 2021: The Heat Is On, both the new and updated climate commitments “fall far short of what is needed to meet the goals of the Paris Agreement, leaving the world on track for a global temperature rise of at least 2.7°C this century.”
12 Years and Counting
This is the twelfth year that UNEP has released an emissions gap report, and this latest iteration is pretty telling in that it found that current commitments will only shave an additional 7.5% off predicted annual GHGs in 2030, compared to the previous round of commitments. “Reductions of 30% are needed to stay on the least-cost pathway for 2°C and 55% for 1.5°C,” UNEP reports.
UNEP says that net-zero pledges could make a big difference. “If fully implemented, these pledges could bring the predicted global temperature rise to 2.2°C, providing hope that further action could still head off the most-catastrophic impacts of climate change,” it points out in a press release. “However, net-zero pledges are still vague, incomplete in many cases, and inconsistent with most 2030 nationally determined conditions (NDCs).”
According to United Nations Climate Change, NDCs embody efforts by each country to reduce national emissions and adapt to the impacts of climate change. The Paris Agreement requires each party to prepare, communicate and maintain successive NDCs that it intends to achieve.
As of Sept. 30, 2021, UNEP says 120 countries, representing just over half of GHG emissions, had communicated new or updated NDCs. In addition, three G20 members have announced other new mitigation pledges for 2030.
Pledging Net-Zero Targets
In order to limit global warming to 1.5°C, UNEP says the world has eight years to take an additional 28 gigatonnes of CO2 equivalent (GtCO2e) off annual emissions, over and above what is promised in the updated NDCs and other 2030 commitments. It says CO2 emissions alone are expected to reach 33 gigatonnes in 2021.
“When all other greenhouse gases are taken into account, annual emissions are close to 60 GtCO2e,” UNEP reports. “So, to have a chance of reaching the 1.5°C target, we need to almost halve GHG emissions. For the 2°C target, the additional need is lower: a drop in annual emissions of 13 GtCO2e by 2030.”
If 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, UNEP points out. However, many of the national climate plans delay action until after 2030, raising doubts over whether net-zero pledges can be delivered. “Twelve G20 members have pledged a net-zero target, but they are still highly ambiguous,” it adds. “Action also needs to be frontloaded to make it in line with 2030 goals.”
