Climate Change is a warming of Earth’s atmosphere and oceans that is caused by human activities. It is causing changes to the natural environment that are already impacting people’s lives, such as droughts, heat waves and floods. It is also affecting the world’s ecosystems, which are undergoing serious stress and may not be able to recover. These changes threaten the wellbeing of all life on Earth.
Climate change is a complex problem with many causes. However, scientists have identified humans as the major cause of global warming by examining fossil fuel consumption and emissions data. Fossil fuels — like coal, oil and gas — release large amounts of carbon dioxide into the air when burned. The carbon dioxide then traps heat from the sun, warms the planet and changes weather patterns.
The world is warming faster than at any time in its history. Since 1880, average temperatures have risen by more than 1 degree Fahrenheit, and the warming is getting faster. In the United States, record highs now outnumber record lows two-to-one.
Warmer temperatures are changing many aspects of our world, including how much rain falls in a region, where and when it rains, and where the snow melts. It is also making sea levels rise and shifting the distribution of plant and animal species.
Most living things can adapt to a changing climate, but ecosystems are reaching their limits. For example, warmer temperatures are increasing outbreaks of pests, invasive species and pathogens that disrupt the life cycles of plants and animals. This makes them less able to cope with other stresses, such as disease or drought.
The most important factor in climate change is greenhouse gases, which are released when fossil fuels are burned and when the lands they grow on are cleared for agriculture or development. They absorb some of the energy from the sun, then radiate it back into space as infrared radiation. This heats the Earth, and as more of these gases are added to the atmosphere, it warms even faster.
Past natural climate changes have been caused by a wide variety of factors, including solar variations, volcanic activity and shifts in ocean circulation. But the current warming is unique because it has been influenced by humans and their activities, such as burning fossil fuels and clearing land.
While the effects of climate change will affect all countries, poorer nations are more vulnerable to its impacts because they have emitted far fewer of the greenhouse gases that cause the warming and tend to be located in tropical regions where higher temperatures could make life unbearable. In addition, they will have a harder time implementing expensive adaptation measures. The climate crisis is already putting their futures at risk; studies show that more than a third of women say they will have fewer children because of climate concerns. It’s also a threat to their livelihoods, because ocean warming and acidification are harming marine productivity that supports 3 billion people worldwide.