CCC Climate Change Committee The Sixth Carbon Budget. The UK’s Path to Net Zero Predictions made in 2020, CONFIRMED 2021
The need to adapt to a changing climate This section summarises the evidence that indicates climate impacts will continue to increase even under a rapid reduction in global emissions and could be greater still if global emissions reductions are not sufficiently rapid to achieve the Paris Agreement.
This emphasises the need for the UK to adapt to the effects of a changing climate and support climate-vulnerable countries around the world to adapt to climate impacts as part of its contribution to the global effort to address climate change. Planning for a range of climate outcomes is prudent even while also aiming to achieve the Paris Agreement. a) Climate risks continue to increase with additional warming The overall level of impacts from climate change will increase with every additional small increment in warming. A growing body of research, summarised by the recent IPCC Special Reports and Fifth Assessment Report, shows how higher levels of warming levels result in increasingly severe and pervasive impacts with effects on humans and ecosystems worldwide.
- 1°C above preindustrial levels: Today’s level of warming is already having significant impacts around the world. The frequency of heatwaves has increased in most land regions.
There are demonstrable impacts on heatrelated mortality particularly for elderly and vulnerable people
Patterns of water availability are changing due to melting land-ice and shifting rainfall in some parts of the world. The frequency and intensity of heavy precipitation has increased at a global scale due to climate change, with knock-on implications for flood risks. Flooding is also increasing in coastal areas as climate change pushes up sea-levels. Climate change is being increasingly linked with making the conditions for wildfires more likely.
Ecosystems and species have been impacted by climate change, with many species changing their geographical extent and/or migratory patterns. Climate change has affected crop yields, with more negative impacts than positive effects.40
- 1.5°C above preindustrial levels: Impacts at 1.5°C warming will be more severe than at present. Hot temperature extremes will increase more rapidly than the global average temperature, and over twice as fast in some parts of the world (e.g. mid-latitude summers). Across the globe there would be around twice as many people affected by river flooding than over the recent past.
The intensity and frequency of heavy rainfall will generally increase. Around 6% of insects, 4% of vertebrates, and 8% of plants would lose >50% of their current species ranges.42 There will be very large impacts on some ecosystems (e.g. coral reefs are projected to decline by a further 70–90% at 1.5°C).
At 2°C warming many regions will experience considerable and damaging climate change impacts including extreme weather and associated detrimental effects on water availability and food production. Heat-related mortality risks increase beyond the risks at 1.5°C. Across the globe there would be around a 170% increase in the number of people affected by river flooding. Climate impacts increase with every bit of additional warming. Significant climate impacts are already being experienced today.
At 2 deg widespread damage to ecosystems would occur with the rate of climate change likely to be too fast for many species to be able to migrate to regions with compatible climates. Around 18% of insects, 8% of vertebrates, and 16% of plants would lose >50% of their geographical range. The risk of irreversible loss of many marine and coastal ecosystems (e.g. coral reefs) increases significantly for warming at 2°C and above. Risks of ‘large-scale singularities’ in the climate system (e.g. triggering inevitable loss of major ice sheets or collapse in the Atlantic meridional overturning circulation) would be ‘moderate’ at this level of warming.
- 3°C above preindustrial levels: Major and severe impacts would be experienced worldwide. For example heat waves would become prevalent across large parts of the world, with around 4.5 billion people exposed to associated serious health risks. Risks to land-based ecosystems would be very high with around 25% of species expected to lose over half of their geographical range by 2100. There would be a high risk of ‘largescale singular events’ at 3°C.
- (July 24th the Economist considers 3 degrees “a pretty likely outcome”)
- 4°C above preindustrial levels: Warming and increases in humidity in many regions could make outdoor working, for example in agriculture, very difficult or even impossible based on people’s current tolerance to heat extremes. Many freshwater and land-based species would face substantial risk of extinction. Large risks to the functioning of the global food system could occur with a substantial chance of large-scale crop failures. Largescale failures of food systems and increases in climate-related extreme events could contribute to large-scale migration of people around the world creating pressures on social and economic systems with difficult to predict geopolitical consequences. Any additional warming is associated with increases in climate change impacts. Poorer and more vulnerable parts of society are expected to be relatively more exposed to impacts from many of these increasing climate risks. However, the UK is not immune from these risks and needs to adapt to the changing climate, even for the lower levels of warming.
The Climate Change Committee is the independent body set up by the government to give them advice on Climate Change. Visit their site and you will find a huge team of our best scientists are and having been working flat out on the issues facing us and promoting policies for the government and making criticisms of what is being done and what has failed to be done. Do go there and browse.