Climate Change is global warming caused by humans’ use of fossil fuels – coal, oil and natural gas – for energy. When these fuels burn, they release heat-trapping greenhouse gases – mostly carbon dioxide (CO2) — into the air. Over the long term, these gases trap heat from the Sun in Earth’s atmosphere, raising its temperature.
Climate change has many negative effects on the planet and on us. It threatens the things we value and need, like clean air, water, food, wildlife, and healthy ecosystems. The effects include rising temperatures, ocean acidification, changes in rainfall patterns, increased droughts and floods, and shifts in the distribution of some species.
Human activities are the primary cause of climate change. Over the past century, fossil fuel consumption has added about 310 billion metric tons of carbon to the atmosphere. This carbon has trapped more heat in the atmosphere than ever before, driving the global average temperature up.
Warmer temperatures are expected to continue – as well as changes in precipitation and storm patterns, sea level rise, retreating glaciers and ice sheets, a changing arctic, and more frequent and severe heat waves.
While all species will be affected by climate change, some will be more vulnerable than others. The most at-risk groups are the urban poor, people who are elderly or young, traditional societies, subsistence farmers, and those living in coastal areas. The crisis also exacerbates existing inequities. Rich nations have emitted the lion’s share of historical CO2 emissions, but it is developing countries that may lack the resources to adapt and will bear the brunt of climate-related disasters.
Some of the impacts of climate change are already here: wildfires are increasing in number and intensity, and some crops have been damaged by heat stress or insect outbreaks. Health-related threats from extreme heat events are on the rise, with more illnesses and deaths occurring, especially among those who have pre-existing conditions or take medications that make them sensitive to high temperatures.
In addition, climate change is accelerating the loss of biodiversity. The rapid changes to habitat are destroying the very environment that wildlife have incrementally adapted to for millennia. Ice-dependent mammals, such as walruses and penguins, will struggle as polar ice melts; shifting ocean temperatures are stressing the algae that nourish coral reefs, which are bleaching in response; and disappearing wetlands mean less place for migratory birds to rest.
A warmer world also means a less diverse world, as some species are moving into regions where they have never existed before and can’t survive. This will reduce biodiversity and can even cause some organisms to become extinct. In the longer term, it can have profound implications for global biodiversity and sustainable development. It can also have negative effects on food security and nutrition. These are just some of the challenges that lie ahead unless we take action now. Taking effective steps to curb climate change can help reduce these risks and protect our quality of life for generations to come.