🔗 Share this article

The gravest potential impacts of the climate emergency for the UK have been detailed by researchers, encompassing a scorching 4C rise in average temperatures to a two-metre increase in sea levels. A separate possibility foresees a plunge of 6C in temperature following the collapse of crucial Atlantic Ocean currents, which would massively disrupt agriculture and energy demand.

Possible Outcomes, Not Predictions

These effects, certain ones are linked to critical climate thresholds, are seen as unlikely but plausible. The team stated that these scenarios addressed a shortfall in forecasting that had rendered the UK unprepared for catastrophic possibilities.

"The worst-case scenarios we have mapped aren’t predictions, but they are possible," commented Nigel Arnell who led the study. "The nation has been making preparations without the methods to plan for worst-case scenarios. We've now provided planners what they need to plan for future conditions they hope never happen, but must not overlook."

A Range of Harsh Climate Scenarios

A further series of severe models details the potential extent of harsh climate between now and the year 2100. These suggest that thermometer readings could rocket in certain periods by up to 6C above average, while precipitation could be triple typical amounts.

The chance of the extreme scenarios happening could not be calculated due to a lack of certainty about what steps will be implemented to address climate change and how the planet's climate will behave. This analysis was likened to security threat evaluations or stress tests for financial systems.

Major Outcome Highlights

• Severe Heating: Worldwide averages soaring past 4C by 2100 could transpire if international cooperation collapses or if strong feedback loops such as the tropical forests dying release its vast reserves of carbon. This would cause intense and enduring heatwaves and dry spells plaguing the UK in summer.
• Ocean Circulation Failure: A key circulation system, the Atlantic meridional overturning circulation (Amoc), is losing strength and losing stability due to ocean warming. A complete failure commencing by 2030 would lead to a 6C cooling in the UK. "Crop production would be severely challenged and water supplies would be drastically changed," noted Arnell.
• Accelerated Coastal Flooding: A rise of 2.0-2.2 metres around the UK by 2100 could occur if polar ice in the polar regions disintegrate quickly, inundating low-lying areas. In contrast to the other scenarios, this risk is already understood by infrastructure experts.
• Aerosol Effect: Temperatures could also be pushed higher by about 0.75C if pollution from industry is drastically reduced. This counterintuitive effect occurs because tiny specks from burning coal scatter solar radiation from reaching the ground.

Building Resilience Against the Unthinkable

These dire projections could be used to inform the building of critical national infrastructure, including housing developments, power generation facilities and water management networks. Understanding these future hazards could also speed the push to cut greenhouse gas emissions.

The research created the severe projections using a mix of observed and historical experience, computer simulations and scientific theory. These outcomes exclude international cascading effects including the agricultural collapse and resource wars.

This work was requested as part of a government’s climate resilience programme. Independent analyses have cautioned that insufficient focus was being allocated to high-consequence, low-probability risks.

An independent advisory body has recommended that the UK needs to "prepare for two degrees of warming" and assess the risks for four degrees. Past policy documents have been criticised as being "very weak" by certain experts.

A government spokesperson commented: "The climate emergency is at the core of the country's focus, both adapting for the future and transitioning to a low-carbon economy. It is crucial that the UK is prepared for the impacts."