Climate Change: What Has Already Changed and What Is to Come

Climate change represents an unprecedented emergency, says the UN. Never before has destruction been so fast, and governments and the international community are failing to tackle the climate crisis. According to the Special Report of the Intergovernmental Panel on Climate Change (IPCC), the destructive impacts of climate change are already visible and the forecasts are not encouraging. Limiting global warming will require limiting carbon dioxide emissions in all sectors of human activity.

The Five Hottest Years

Earth’s temperature has been rising but the past five years have been the warmest since records exist. July 2019 was the hottest month ever. The term “temperature anomaly” means a deviation from a reference value or long-term average. A positive anomaly indicates that the observed temperature was warmer than the reference value, while a negative anomaly indicates that the observed temperature was lower than the reference value. Over the past 30 years, monthly anomalies have always been higher than the 20th century average.

The Earth Warms and Warms

This NASA animation allows you to see the progression of global surface temperature anomalies between 1880 and 2018. Higher than normal temperatures are shown in shades ranging from yellow to red. The lowest ones are shown in shades of blue. The last map shows the global average temperature anomaly calculated for five years, from 2014 to 2018.

The main gases in the atmosphere are nitrogen and oxygen. Together they make up about 99% of the atmosphere. There are other gases, in small quantities, including greenhouse gases (GHG) that have the ability to retain the infrared radiation emitted by the Earth, preventing it from escaping into space causing the phenomenon called the greenhouse effect. The greenhouse effect is a natural process that determines the Earth’s climate and causes the Earth’s temperature to be higher than it would be in the absence of the atmosphere.

Main factors contributing to greenhouse gas emissions

  • Burning of coal, oil or gas
  • Deforestation: trees help regulate the climate by absorbing the CO2 present in the atmosphere. When they are slaughtered, this beneficial effect disappears and the carbon ceases to be stored and remains in the atmosphere, reinforcing the greenhouse effect.
  • Livestock farming: cows and sheep produce large amounts of methane during food digestion
  • Use of nitrogen-containing fertilizers, these produce nitrous oxide (N20) emissions

Of the greenhouse gases, CO2 is responsible for 63% of global warming (check out our article on reducing carbon footprint). Its concentration in the atmosphere is now 40% higher than at the beginning of the industrial era. Global average annual concentration of carbon dioxide (CO2) in the atmosphere, measured in parts per million (ppm).

Dramatic consequences in the worst case scenario

Millions of people in sub-Saharan Africa, Latin America and Southeast Asia will have to leave their homes, as will populations in coastal regions and islands that will disappear due to rising sea levels. According to the IPCC, due to the loss of crops, loss of work, the need to leave their homes, the rise in food and essential goods prices or the increase in diseases, millions of people will be vulnerable to poverty by 2030, including some “fringes”. More fragile of the middle class in developed countries.

Torrential rains, prolonged droughts, heat waves, tornadoes and other extreme weather events are already more frequent. Some plant and animal species are increasingly vulnerable and at risk of extinction due to changes in climate and their habitat.

The polar caps and glaciers are melting faster than expected, releasing methane and carbon dioxide from permafrost, which, combined with a loss of white ice that reflects heat, contributes to accelerating global warming.