As the atmosphere heats up, it changes wind and ocean patterns, upsetting the weather we’ve built farms and cities around for the last 6000 years. This means that everywhere is experiencing some change in rainfall or temperature. This can be a problem on its own, but in many places, these changes are extreme.
- Storms and Floods A hotter ocean causes more evaporation, meaning clouds pick up more water before dumping it on the land. This means that places which already experience cyclones, typhoons and hurricanes are experiencing more and bigger storms. In cold regions, melting snow can also lead to floods, as can increased rainfall.
- Droughts If rain is falling in once place, it’s not falling in another. As rainfall patterns change, and higher temperatures make water evaporate faster from the land, many places are experiencing drought. For example, changes to the monsoon can lead to floods in Asia and drought in Australia.
- Fires More evaporation and less rainfall leaves vegetation dry. This combined with higher temperatures makes it very easy for fires to spread. We have seen this recently in Brazil, Australia, the United States, where dozens of people died, thousands had to flee their homes, and millions of acres were destroyed. Fires are particularly devastating as they release more carbon into the atmosphere.
As the atmosphere heats up, it changes wind and ocean patterns, upsetting the weather we’ve built our farms around for 6000 years. Too much rain drowns crops, too little causes drought, while more heat leads to pests and diseases, that can kill crops and livestock. All of this means more hunger.
As the ice caps over Greenland and Antarctica melt, they raise the level of the sea. Water also expands when it is hot, so part of sea level rise is simply the ocean getting bigger. Low lying nations like the Pacific Islands and Bangladesh are particularly vulnerable. The hot ocean cannot store the carbon dissolved in it (think of the bubbles that form when you boil water) so as it gets warmer it releases more carbon, and speeding up climate change even more.
As temperatures get warmer, heat-loving insects like mosquitoes can travel further, bringing diseases like malaria, dengue and zika to more people. Climate change also causes deaths from heat stroke, while the same fossil fuels and forest fires that cause climate change also increase air pollution, leading to cancer, heart disease, respiratory conditions, impaired brain development, and premature births.
CONFLICT & MIGRATION
As all of these problems get worse, people are forced to move in search of safety. Some Pacific Islanders have already left their homes due to sea level rise, while floods and droughts everywhere from South America, to India, to Sudan are also causing migration. It is likely that competition over scarce resources, especially with more migration, will lead to new conflicts, and old ones breaking out again.
Extreme weather such as floods and fires can destroy animal and plant habitats, as can human expansion fleeing climate change. Some animals need the cold to feed or breed, and some simply die at higher temperatures. As the ocean heats, for example, corals begin to die, taking away the backbone of the marine ecosystem. More than 60% of all animals have been wiped out by humans in the last 50 years.
At least 1 million species of animals and plants are threatened with extinction. This is not just bad for them, but bad for people, as we rely on healthy ecosystems. Insects pollinate our crops, millions of people rely on fish for food, many plants and animals produce medicine, and we all breathe oxygen from plants and algae.