🔗 Share this article

The most severe potential impacts of the climate crisis for the UK have been mapped by experts, including a scorching 4C rise in temperatures to a two-metre surge in ocean levels. A separate possibility foresees a drop of 6C in temperatures following the shutdown of critical Atlantic Ocean currents, which would massively disrupt food production and power requirements.

Plausible Outcomes, Not Guarantees

These impacts, a number of which are linked to climate tipping points, are seen as improbable but credible. The team explained that these scenarios plugged a hole in forecasting that had rendered the UK not ready for worst-case results.

"The severe weather events we have mapped should not be seen as certainties, but they are credible," commented the lead researcher who oversaw the research. "The UK has been planning without the frameworks to plan for catastrophic outcomes. We've now supplied decision-makers what they need to prepare for future conditions they hope never happen, but must not overlook."

A Suite of Harsh Climate Scenarios

A second set of severe models maps the projected severity of extreme weather between now and the year 2100. These suggest that temperatures could skyrocket in some months by up to 6C higher than historical levels, while precipitation could be triple standard measurements.

The chance of the extreme scenarios occurring cannot be precisely determined due to a lack of certainty about what steps will be enacted to combat global warming and how the Earth's systems will behave. This research was compared to defence planning or scenario planning for economic stability.

Major Possibility Elements

• 4C Temperature Rise: Planetary heating exceeding 4C by 2100 could occur if international cooperation breaks down or if strong feedback loops like the Amazon basin perishing unleash its vast reserves of carbon. This would result in intense and enduring heat domes and droughts affecting the UK in summer.
• AMOC Shutdown: A critical sea current, the North Atlantic current, is losing strength and becoming unstable due to ocean warming. A complete failure commencing by 2030 would lead to a 6C cooling in the UK. "Agriculture would face immense difficulties and water resources would be drastically changed," said the lead researcher.
• Rapid Sea Level Rise: A rise of 2.0-2.2 metres around the UK by 2100 could occur if polar ice in the Arctic and Antarctic collapse rapidly, flooding low-lying areas. Unlike the other scenarios, this threat is already known by planners.
• Aerosol Effect: Temperatures could also be driven up by about 0.75C if industrial aerosols is sharply cut. This unexpected result occurs because tiny specks from fossil fuel combustion reflect solar radiation from reaching the ground.

Planning for the Unthinkable

These dire projections could be applied to guide the construction of long-term infrastructure, for example expanded cities, energy plants and urban drainage systems. Awareness of these climate risks could also hasten the transition to cut greenhouse gas emissions.

The study developed the severe projections using a mix of real-world events, digital projections and climate physics. The possibilities omit broader worldwide issues such as the global food shortages and geopolitical instability.

The project was initiated as part of a official risk assessment framework. Earlier reports have warned that insufficient focus was being paid to high-consequence, low-probability risks.

The government's climate advisors has said that the UK must "become resilient to moderate heating" and examine the risks for four degrees. Past policy documents have been criticised as being "insufficient" by certain experts.

An official statement said: "The climate emergency is at the heart of the country's focus, both adapting for the future and becoming a low-carbon economy. It is crucial that the UK is prepared for the effects."