Ahead of COP26, London- based policy institute Chatham House, the Royal Institute of International Affairs has issued a grim warning on climate change - the world is dangerously off track to meet the Paris Agreement goals.

In its climate change risk assessment 2021, the independent think tank says the risks are compounding, and without immediate action the impacts will be devastating in coming decades.

At COP26, the governments of highly emitting countries will have a critical opportunity to accelerate emissions reductions through ambitious revisions of their nationally determined contributions (NDCs).

Intended for heads of government, the assessment says that if emissions follow the trajectory set by current NDCs, there is a less than 5% chance of keeping temperatures well below 2°C above pre-industrial levels, and less than 1% chance of reaching the 1.5°C target set by the 2015 Paris Agreement.

According to Chatham House, unless NDCs are dramatically increased, and policy and delivery mechanisms are revised accordingly, many of the climate change impacts described in the research paper are likely to be locked in by 2040, and “become so severe they go beyond the limits of what nations can adapt to.”

As well as the immediate physical and socio-economic consequences of changes in climate, the research paper captures the systemic cascading risks likely to arise as these direct risks and impacts compound to affect whole systems, including people, infrastructure, the economy, societal systems and ecosystems.

Among the report’s key findings:

• If policy ambition, low-carbon technology deployment and investment follow current trends, 2.7°C of warming by the end of this century is likely, relative to pre-industrial temperatures. A plausible worst case of 3.5°C is possible (10% chance). These projections assume Paris Agreement signatories meet their NDCs. If they fail to do so, the probability of extreme temperature increases is non-negligible.
• Any relapse or stasis in emissions reduction policies could lead to a plausible worst case of 7°C of warming by the end of the century (10% chance).
• If emissions follow the trajectory set by current NDCs, there is a less than 5% chance of keeping temperatures well below 2°C relative to pre-industrial levels, and less than 1% chance of reaching the 1.5°C Paris Agreement target.
• There is currently a focus on net zero pledges, and an implicit assumption these targets will avert climate change. However, net zero pledges lack policy detail and delivery mechanisms, and the deficit between targets and the global carbon budget is widening every year.
• Unless NDCs are dramatically increased, and policy and delivery mechanisms are commensurately revised, many of the impacts described in this research paper are likely to be locked in by 2040 and become so severe they go beyond the limits of what nations can adapt to.
• The governments of highly emitting countries have an opportunity to accelerate emissions reductions through ambitious revisions of their NDCs, significantly enhancing policy delivery mechanisms, and incentivizing rapid large-scale investment in low-carbon technologies. This will lead to cheaper energy and avert the worst climate impacts.
• If emissions do not come down drastically before 2030, then by 2040 some 3.9 billion people are likely to experience major heatwaves, 12 times more than the historic average. By the 2030s, 400 million people globally each year are likely to be exposed to temperatures exceeding the workability threshold. Also by the 2030s, the number of people on the planet exposed to heat stress exceeding the survivability threshold is likely to surpass 10 million a year.
• To meet global demand, agriculture will need to produce almost 50% more food by 2050. However, yields could decline by 30% in the absence of dramatic emissions reductions. By 2040, the average proportion of global cropland affected by severe drought will likely rise to 32% a year, more than three times the historic average.
• By the 2040s, the probability of a 10% yield loss, or greater, within the top four maize producing countries (the US, China, Brazil and Argentina) rises to between 40% and 70%. These countries currently account for 87% of the world’s maize exports. The probability of a synchronous, greater than 10% crop failure across all four countries during the 2040s is just less than 50%.
• Globally, on average, wheat and rice together account for 37% of people’s calorific intake. The central 2050 estimate indicates that more than 35% of the global cropland used to grow both these critical crops could be subject to damaging hot spells. But this vulnerability could exceed 40% in a plausible worst-case scenario. The central estimate for 2050 also indicates these same global cropland areas will be impacted by reductions in crop duration periods of at least 10 days, exceeding 60% for winter wheat, 40% for spring wheat, and 30% for rice.

By 2040, almost 700 million people a year are likely to be exposed to droughts of at least six months’ duration, nearly double the global historic annual average. No region will be spared, but by 2040 East and South Asia will be most impacted – with, respectively, 125 million and 105 million people likely to experience prolonged drought. Across Africa, 152 million people each year are likely to be impacted.

Chatham House is warning that cascading climate impacts can be expected to cause higher mortality rates, drive political instability and greater national insecurity, and fuel regional and international conflict.

The cascading risks that participants identified greatest concern over were the interconnections between shifting weather patterns, resulting in changes to ecosystems and the rise of pests and diseases.

Combined with heatwaves and drought, these impacts will likely drive unprecedented crop failure, food insecurity and migration. In turn, all will likely result in increased infectious diseases, and a negative feedback loop compounding each impact.

Physical risk events from heatwaves, wildfires, floods and droughts are of particular concern because of their potential to impact food security, energy and water infrastructure, as well as lead to business defaults on a scale that the insurance industry would be unable to cope with.

Click here to download Chatham House Climate Change Risk Assessment 2021