Consequences when the Earth's temperature exceeds the safe threshold
Global food production may decrease by 14% by 2050, the economies of many countries will suffer double damage due to reduced labor productivity, when the Earth's temperature increases beyond 1.5 degrees Celsius.
Limiting global temperature rise to 1.5 degrees Celsius above pre-industrial levels is the goal 195 countries agreed on at the 2015 Paris Agreement. This milestone was proposed by a group of small island states. Tony de Brum, the late Foreign Minister of the Marshall Islands, once explained that this increased threshold was a milestone that would ensure they "could survive" and the country would escape sinking under the sea.
A recent report from the United Nations Environment Program (UNEP) predicts that the Earth's temperature will exceed the safe threshold in the period 2026-2030, due to emissions from coal, oil and gas.
As Mr. Tony feared a decade ago, the danger of this situation is rising sea levels, threatening to submerge more than 20 small island nations and coastal areas. Tuvalu is forecast to sink in the next 24 years. Last year, they were the first country to implement a "climate migration" program, sending hundreds of people to Australia each year to continue to survive.
According to UNEP, extreme climate phenomena will cause chain risks, directly threatening human life and the stability of the planet.
Agriculture is a field that will be greatly affected by global warming. Cultivation, animal husbandry, and aquaculture activities all risk reducing productivity, causing famine and threatening the livelihoods of billions of people.
For example, with crops, just an additional 0.5 degrees Celsius will cause productivity to decline, pushing up food prices. Global food production could decrease by 14% by 2050, if effective adaptation measures are not taken.
As the Earth's temperature heats up, the economies of many countries are at risk of suffering double losses due to reduced labor productivity, according to the Limiting overshoot report published by UNEP on September 2. For example, in Ghana, heatwaves and related illnesses are forecast to reduce labor productivity in the agricultural sector by about 8.5%, and the manufacturing sector by 2.6% by 2050.
In Argentina, expected annual property damage due to flooding is expected to reach $1.4 billion. The country will suffer a 125% increase in losses if the frequency of floods doubles.
For Middle Eastern countries, such as Iraq, modeling results show increased drought conditions. If water supply is reduced by 20%, the country will lose about 3.9% of GDP.
Extreme heat is a major threat to human life. According to UNEP, extreme heat waves, which only appear once every hundred years, now appear every decade, progressing to become a new normal phenomenon when temperatures increase by 1.5-2 degrees Celsius.
The "heat island" phenomenon will cause urban residents to feel the heat increase by a few degrees. Increased heat levels bring pathogens from intermediate species (such as mosquitoes), increasing illnesses and deaths.
According to the World Health Organization (WHO), climate change will cause 250,000 deaths each year, due to malnutrition, malaria, diarrhea and heatstroke alone. The cost of health damage is estimated at 2-4 billion USD per year, with a major impact on regions with rising temperatures such as Central America and Southeast Asia.
Global warming also increases disasters such as storms, floods and landslides. An increase of 1.5 degrees Celsius also triggers "tipping points" - thresholds where small changes can lead to large, continuous chains of consequences with irreversible risk.
One climate tipping point is the Greenland ice sheet. The world's second largest ice sheet will melt irreversibly at a temperature increase of 1.5 degrees Celsius. If it melts completely, it could cause sea levels to rise by 7.2 m. In just the past two decades, Greenland has lost 5,100 billion tons of ice.
Another tipping point is the Amazon - the largest tropical rainforest on the planet. In the past 10 years, this forest has experienced three "extremely severe" droughts, which previously only happened once every hundred years. This forest is quickly losing its ability to recover from damage caused by drought, fire and deforestation.
Faced with this situation, the United Nations hopes to achieve the most optimistic scenario. Accordingly, global temperature will exceed the threshold, but will only peak at 1.8 degrees Celsius, then gradually decrease to below 1.5 degrees Celsius by the end of this century.
However, the report also notes that even if humanity releases negative emissions and lowers global temperatures to below 1.5 degrees Celsius by 2100, it is unlikely that the world and climate will be returned to a normal state.
