Climate changes will increase in all regions in the coming decades, scientists say. They say many of the changes were unseen in thousands of years. In addition, some changes such as sea level rise would be irreversible for thousands of years.
Scientists with latest advances in climate science came together to compile the Intergovernmental Panel on Climate Change (IPCC) Report.
The use of fossil energy – oil, coal, gas and biomass – is responsible for about 85% of carbon dioxide (CO2) emissions caused by human activities. CO2 is the most abundant of gases causing global warming accounting for about 75%.
The Earth absorbs some solar energy coming from the Sun and sends some heat back to space. But some of the heat the Earth sends back to space is sent back to Earth by CO2 in the atmosphere thus warming Earth’s climate.
The report expects global temperature to reach or exceed 1.5C over the next 20 years.
If global warming reaches 1.5C, there will be increasing heat waves, longer warm seasons and shorter cold seasons. If Earth warms to 2C, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.
Nations are working on ambitious mitigation actions to limit warming to 1.5°C.
When estimated over the entire historical period (1850–2020), the contribution of natural variability to global surface warming is between -0.23C and 0.23C. This is small compared to the warming of about 1.1C observed during the same period, which has been almost entirely attributed to the human influence – IPCC Report.
If warming continues Indian Ocean water will continue eroding Kenya’s shoreline, the report shows. Around the African continent shoreline retreat rates of up to one metre in a year have been recorded between 1984 and 2015.
Africa has lost coastal area of 39,536.9 acres and 113,668 acres over the period along the Atlantic and Indian ocean coasts.
The report’s projects a vast majority of sandy coasts in the region will see their shorelines retreat throughout this century.
If warming continues, the reports say by 2100 Kenya’s Indian Ocean coastline would have retreated by more than 100 metres.
The report says that it is highly likely that most coastal and ocean related hazards in Africa will increase over this century.
“Relative sea-level rise is virtually certain to continue around Africa, contributing to increased coastal flooding in low-lying areas and shoreline retreat along most sandy coasts,” says the report. “Marine heatwaves are also expected to increase around the region over the 21st century.”
Projected decreases in snow, glaciers
African glaciers are located in East Africa and more specifically on Mount Kenya, the Rwenzori Mountains and Mount Kilimanjaro.
The report expects African mountains to lose the largest mass of glaciers even under low-emission scenarios. It says that even imbalances between the Mount Kilimanjaro glaciers and present-day climate would be enough to eliminate the mountain’s glaciers by 2060.
In addition, East African mountains will see their snow water and snow cover season duration decline.
The report says it is certain African snow and glaciers have very significantly decreased in the last decades. “This trend will continue over the 21st century,” it said.
Projected increases in intensity of heavy rainfall and flooding
East Africa has experienced strong rainfall changes and intense wet spells. This has led to widespread flooding in Ethiopia, Somalia, Kenya and Tanzania.
The report says West and East Africa regions will have a west-to-east pattern of decreasing-to-increasing rainfall. This means that if West Africa is having increasing rainfall, East Africa will have decreasing rainfall and the other way.
The report expects rainfall to decrease in the Africa’s northernmost and southernmost regions.
Most African regions will see an increase in heavy rainfall that could lead to floods. This would happen even though there would be aridity, droughts and fires in North Africa, Southern Africa and Western Africa.
So, what can we do?
The report provides new estimates of the chances of crossing the global warming level of 1.5C in the next decades. It finds that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5C or even 2C will be beyond reach.
Greenhouse gases are gases in the atmosphere such as water vapour, carbon dioxide, methane and nitrous oxide that can trap heat in the atmosphere.
The report shows that human actions still have the potential to determine the future course of climate. It says evidence is clear that carbon dioxide is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.
The report’s co-chair Panmao Zhai said stabilising the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions. “Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” he said.
Ms Inger Andersen, executive director, United Nations Environment Programme, said it was “time to get serious because every tonne of CO2 emission adds to global warming.”
She told governments to reduce the amount of gaseous carbon compounds their countries release.
“[Governments] must decarbonise faster,” Ms Andersen said during the release of the report on 9 August 2021.
She asked governments to restore natural systems that draw down carbon and cut out methane and other greenhouse gases faster.
Ms Andersen said this generation can change systems that would stop the planet warming.
“We can’t undo the mistakes of the past,” she said. “But this generation of political and business leaders, this generation of conscious citizens, can make things right.”