Global Climate Projections

What are the projected changes in global climate?
Climate projections suggest that global temperatures are expected to continue to rise, with the magnitude depending on future greenhouse gas emissions and the SSP scenarios. The IPCC projects that global average temperatures could increase by 1.5°C to 4.4°C by the end of the century, compared to pre-industrial levels. Temperature maps show that land is warming more than the oceans and the Arctic and Antarctic regions are warming more than the tropics. Changes in precipitation patterns are expected, with some regions experiencing more frequent and intense droughts, while others experience more frequent and intense rainfall. Sea levels are expected to continue to rise, with IPCC projections of 0.28m to 1.88m by the end of the century.

How is the UK climate expected to change?
UKCP projects that average temperatures in the UK will increase throughout the 21st century, with the magnitude of warming depending on future greenhouse gas emissions. In a high-emission scenario, summer temperatures could increase by 1.3°C to 5.1°C and winter temperatures by 0.6°C to 3.8°C by 2070. Small shifts in average temperature can substantially increase the frequency and intensity of extreme heat events and reduce extreme cold events. Winter rainfall is likely to increase while summer rainfall is likely to decrease, particularly in southern and eastern England, and heavy rainfall events are expected to become more frequent, raising flood risk. Sea level rise will continue around the UK, with regional differences due to land movement since the last ice age; for example, London could see rises of 0.53m to 1.15m by the end of the century under a high-emission scenario.

What is the value of climate attribution?
Climate attribution determines the extent to which human activities (such as greenhouse gas emissions) have contributed to observed climate changes and specific extreme events. By quantifying human influence, attribution helps policymakers and planners evaluate the costs and benefits of mitigation and adaptation options and provides evidence to justify action to reduce climate risks.

What are climate tipping points?
Climate tipping points are thresholds in the Earth’s climate system that can trigger rapid, potentially irreversible changes when crossed. They arise from complex feedbacks between different climate components. Examples include the melting of the Greenland and Antarctic ice sheets, collapse of the Atlantic Meridional Overturning Circulation (AMOC), and release of methane from thawing permafrost. Crossing these tipping points could accelerate warming and disrupt global climate patterns, reinforcing the need to limit emissions and increase monitoring and resilience.