The Intergovernmental Panel on Climate Change’s landmark (IPCC) 2021 report left many wondering whether the world can actually limit global warming to 1.5 degrees C (2.7 degrees F), the threshold scientists say is necessary for avoiding the most dangerous climate impacts. New research by WRI and Climate Analytics shows that G20 countries, which account for around 75% of global greenhouse gas emissions, can get the world a large part of the way towards that target — if they greatly increase their ambition.
Countries’ current climate plans — including 2030 emissions-reduction pledges (known as NDCs) and legally binding net-zero targets — will only limit warming to 2.4 degrees C (4.32 degrees F) by 2100, setting the world up for increasingly severe wildfires, droughts, floods and more. If G20 countries fully enact the additional targets they’ve announced but not yet formally adopted, temperature rise could be limited to 2.1 degrees C (3.78 degrees F).
The paper finds that if all G20 countries set ambitious 2030 emissions-reduction targets and commit to reach net-zero emissions by mid-century, global temperature rise could be limited to 1.7 degrees C (3.06 degrees F) in 2100, keeping the 1.5-degree C goal within reach.
Specifically, the paper models the effect on global temperature if -- in addition to existing pledges — developed countries set net-zero greenhouse gas emissions targets by 2050, developing countries set net-zero carbon dioxide emissions targets by 2050, and all G20 countries align their 2030 emissions-reduction targets with global, cost-effective pathways that limit warming to 1.5 degrees C.
This analysis underscores how essential it is for G20 nations to step up their climate action commitments ahead of the UN climate summit (COP26) in November 2021.
Why is limiting global temperature rise to 1.5 degrees C so important?
The extreme weather events we’re seeing today — like record-breaking heat and wildfires in the U.S., Canada and Russia, and severe flooding in Europe and China — are taking place with warming of just 1.1 degrees C (1.98 degrees F) above pre-industrial levels.
Keeping temperature rise to 1.5 degrees C will not stop these extreme weather events, but will avoid more dangerous climate impacts under higher temperatures. Breaching 1.5 degrees C would put millions of people at a much higher risk of life-threatening heatwaves, floods, droughts and poverty. Every fraction of a degree matters when it comes to the severity of climate impacts.
For example, here is a breakdown of the differences between 1.5 degrees C and 2 degrees C of temperature rise:
How much more do G20 countries need to cut 2030 emissions to limit warming to 1.5 degrees C?
Nearly every G20 member would need to enhance its 2030 NDC in order to reduce its emissions at a pace that is consistent with limiting warming to 1.5 degrees C.
The graphic below shows the percentage of the global ambition gap for 2030 that each G20 country would close by adopting a “1.5-degree-C-aligned” NDC:
Several G20 countries have submitted enhanced NDCs that narrow the gap to 1.5 degrees C. To date, Argentina, Canada, the European Union, and U.S. have all set 2030 emissions-reduction targets that are stronger than their previous NDCs submitted in 2015, though they’re not yet fully 1.5 degrees C-aligned. The UK set a 2030 target in the 1.5-degrees-C-compatible range.
Japan, South Africa and South Korea announced their intention to enhance their 2030 emissions-reduction targets by COP26, but have not yet formally communicated them to the UN.
China, India, Saudi Arabia and Turkey have yet to submit updated 2030 NDCs at all.
Other countries, including Australia and Indonesia, submitted climate plans that maintained the same level of emissions in 2030 as their 2015 NDCs. Russia’s updated NDC is marginally stronger than its previous one, but still allows emissions in 2030 to be higher than where they are projected to be under the country’s current policies. In the same vein, Brazil and Mexico submitted updated NDCs with 2030 emissions targets that would allow higher emissions than what they had committed to in previous NDCs.
Moreover, the report notes that while many of the net-zero targets set by some G20 countries have helped lower projected temperature levels, they require very steep emissions cuts from 2030 levels to achieve net-zero emissions by mid-century. In many cases, these steep reductions are challenging or simply beyond what global models consider to be feasible. The G20 will need to rapidly cut emissions in the 2020s to improve the credibility of their net-zero targets.
Besides deeper emissions reductions in G20 countries, what else needs to happen to limit warming to 1.5 degrees C?
Without ambitious action by G20 countries, limiting warming to 1.5 degrees C is out of the question. And in order to fully close the gap from 1.7 degrees C to 1.5 degrees C, we’ll need action from non-G20 countries and emissions cuts from international aviation and shipping, too. Encouragingly, a number of non-G20 countries have shown tremendous leadership in putting forward ambitious 2030 emissions-reduction pledges and adopting net-zero targets.
Ambitious action from developing countries will require that developed nations — in addition to setting ambitious emissions-reduction targets for themselves — provide adequate climate finance, starting by making good on the $100 billion they committed to provide annually by 2020.
What should major economies do now?
Just this month, a global survey found that 74% of people in G20 nations support the idea that their country’s economic priorities “move beyond profit and increasing wealth and focus more on human wellbeing and ecological protection.” Our research shows the pivotal role that the G20 can play in safeguarding our future and keeping global temperature rise to safe levels. What the world requires now is bold leadership from the G20 to get us on a safe, climate-resilient path.
The upcoming UN General Assembly, G20 Summit in Rome in October 2021 and COP26 in November 2021 present critical opportunities. Actions G20 countries should take before then include:
Submit NDCs that significantly deepen emissions reductions for 2030;
Commit to mid-century net-zero targets and ensure their 2030 targets align with longer-term goals; and
Step up public climate finance pledges (by developed countries) and mobilize private finance.
It is still possible to limit global temperature rise to 1.5 degrees C, but that window is closing fast. G20 countries must step up to keep that window open and secure a safer future for us all.