🔗 Share this article Profound Turmoil Projected: The United Kingdom's Worst-Case Climate Crisis Outcomes Laid Bare by Experts The direst possible consequences of the climate crisis for the UK have been mapped by experts, ranging from a scorching 4C rise in average temperatures to a two-metre increase in sea levels. Another scenario envisions a decline of 6C in temperature following the failure of key Atlantic Ocean currents, which would profoundly upset food production and energy needs. Possible Outcomes, Not Guarantees These effects, a number of which are linked to irreversible climate shifts, are seen as low probability but possible. The researchers stated that these models plugged a hole in forecasting that had rendered the UK unprepared for catastrophic possibilities. "The severe weather events we have outlined should not be seen as certainties, but they are credible," commented Nigel Arnell who directed the research. "The UK has been formulating policy lacking the tools to assess extreme possibilities. We've now supplied decision-makers what they need to get ready for climate outcomes they hope never happen, but can’t afford to ignore." A Range of Extreme Weather Scenarios Another collection of severe models details the possible scale of extreme weather between now and the year 2100. These show that thermometer readings could skyrocket in some months by up to 6C above historical levels, while rainfall could be three times standard measurements. The probability of the catastrophic events occurring remains uncertain due to uncertainty about what steps will be taken to tackle climate change and how the Earth's systems will respond. This approach was compared to security threat evaluations or scenario planning for the banking sector. Major Possibility Elements Four-Degree Warming: Global temperatures soaring past 4C by 2100 could happen if climate action breaks down or if powerful amplifying effects like the tropical forests becoming a net carbon source unleash its vast reserves of carbon. This would result in intense and enduring heat domes and dry spells plaguing the UK in summer. AMOC Shutdown: A major ocean current, the Atlantic meridional overturning circulation (Amoc), is losing strength and losing stability due to global heating. A complete failure starting around 2030 would lead to a six-degree temperature drop in the UK. "Agriculture would be severely challenged and water supplies would be completely altered," explained the lead researcher. Accelerated Coastal Flooding: A increase of 2.0-2.2 metres around the UK by 2100 could take place if polar ice in the Arctic and Antarctic melt abruptly, flooding coastal cities and towns. In contrast to the other scenarios, this threat is already known by infrastructure experts. Pollution Paradox: Global averages could also be driven up by about 0.75C if industrial aerosols is sharply cut. This paradoxical outcome occurs because aerosol particles from burning coal scatter solar radiation from reaching the ground. Building Resilience Against the Unthinkable The worst-case scenarios could be applied to guide the development of major projects, including housing developments, power generation facilities and flood defences. Understanding these future hazards could also accelerate the transition to cut carbon pollution. The study formulated the worst-case scenarios using a blend of observed and historical experience, computer simulations and climate physics. The scenarios do not take into account international cascading effects including the global food shortages and increased conflict. The project was initiated as part of a national climate resilience programme. Earlier reports have stated that too little consideration was being allocated to low‐likelihood but high‐impact risks. Official experts has said that the UK needs to "adapt to 2C" and evaluate the risks for 4C. Past policy documents have been criticised as being "insufficient" by certain experts. An official statement said: "The climate emergency is at the center of our national priorities, both preparing for impacts and transitioning to a clean energy superpower. It is essential that the UK is prepared for the effects."