🔗 Share this article

The gravest projected effects of the global heating for the UK have been detailed by experts, encompassing a scorching 4C jump in temperatures to a 6.5-foot surge in sea level. An alternative projection foresees a decline of 6C in temperatures following the shutdown of key Atlantic Ocean currents, which would severely impact farming and energy needs.

Possible Events, Not Guarantees

These effects, some of which are associated with climate tipping points, are seen as low probability but plausible. The researchers stated that these models addressed a shortfall in risk assessment that had left the UK not ready for extreme outcomes.

"The worst-case scenarios we have mapped aren’t predictions, but they are credible," said the professor who oversaw the research. "The UK has been planning in the absence of the tools to test against catastrophic outcomes. We've now provided decision-makers what they need to get ready for climate outcomes they pray never occur, but must not overlook."

A Range of Harsh Climate Scenarios

Another collection of severe models maps the potential extent of extreme weather between now and the end of the century. These suggest that temperatures could skyrocket in certain periods by up to 6C higher than average, while rainfall could be three times standard measurements.

The probability of the worst-case outcomes occurring could not be calculated due to unknown factors about what steps will be implemented to address climate change and how the climate system will behave. This analysis was compared to national security risk assessments or scenario planning for the banking sector.

Key Outcome Details

• Severe Heating: Planetary heating rising well above 4C by 2100 could occur if emissions cuts fails or if powerful amplifying effects including the tropical forests becoming a net carbon source unleash its vast reserves of carbon. This would cause extreme and prolonged heatwaves and water shortages plaguing the UK in summer.
• Atlantic Current Collapse: A critical sea current, the AMOC, is losing strength and showing signs of collapse due to global heating. A complete failure beginning in 2030 would lead to a six-degree temperature drop in the UK. "Agriculture would be severely challenged and freshwater availability would be drastically changed," said the professor.
• Sudden Ocean Inundation: A rise of 2.0-2.2 metres around the UK by 2100 could happen if glaciers in the polar regions disintegrate quickly, inundating low-lying areas. Unlike the other scenarios, this possibility is already known by infrastructure experts.
• Clean Air Warming: Temperatures could also be driven up by about 0.75C if pollution from industry is rapidly cleaned up. This paradoxical outcome occurs because tiny specks from industrial activity scatter solar radiation from warming the ground.

Building Resilience Against the Unthinkable

The severe models could be applied to guide the building of critical national infrastructure, such as expanded cities, energy plants and water management networks. Awareness of these climate risks could also hasten the drive to slash greenhouse gas emissions.

The research created the extreme models using a mix of past data and records, digital projections and scientific theory. The possibilities omit international cascading effects including the devastation of food supplies and resource wars.

The project was commissioned as part of a government’s risk assessment framework. Previous assessments have cautioned that insufficient focus was being paid to low‐likelihood but high‐impact risks.

The government's climate advisors has recommended that the UK needs to "become resilient to moderate heating" and assess the threats for four degrees. Earlier government strategies have been criticised as being "inadequate" by certain experts.

A national response commented: "Climate change is at the heart of this government’s agenda, both adapting for the future and establishing itself as a low-carbon economy. It is essential that the UK is ready for the impacts."