The Earth’s atmosphere acts like a greenhouse, trapping some of the Sun’s energy that would otherwise be lost to space. This is called the “greenhouse effect.” The main gases that cause this are carbon dioxide, methane, nitrous oxide and some artificial chemicals such as chlorofluorocarbons. Human activities, especially the burning of fossil fuels (coal, oil and natural gas), agriculture and land clearing, are increasing the concentration of these heat-trapping gases in the atmosphere. This is causing the Earth to warm.
The increase in temperature has many harmful impacts, including longer summers and shortened winters, greater temperatures, changes in rainfall patterns, rising sea levels (due to the expansion of warmer water), melting glaciers in cold regions, a weaker ozone layer and more. These changes also affect animal and plant life by altering their habitats and affecting their growth.
Climate change is happening now and will continue to happen unless we take action. This means reducing our fossil fuel consumption, increasing renewables and switching to electric vehicles. It also means keeping population growth under control and limiting the over-exploitation of natural resources. Taking these actions will help us avoid the worst effects of global warming and keep it below 1.5°C. However, if emissions continue to rise as they have been since the start of the industrial revolution, we will have a harder time achieving that goal. The latest IPCC report warns that we are on track to pass the 1.5°C mark within a few decades.