Climate Change is a complex issue that affects all aspects of Earth’s life, from the weather to our food, water, energy, transportation, agriculture, ecosystems and human health. It is caused by a combination of emissions from fossil fuels and other industrial activities, changes in the oceans and land surfaces, and other factors that are in turn affected by natural variations like the El Nino Southern Oscillation and volcanic eruptions.
The biggest factor that drives climate change is the concentration of greenhouse gases in the atmosphere, mainly carbon dioxide and methane. These are emitted when we burn fossil fuels like coal, gas and oil. As a result, they trap heat in the atmosphere and radiate it back to space, warming the planet.
Over the past few centuries, human activities have increased the amount of carbon dioxide in the atmosphere. This has risen from 280 parts per million to more than 420 ppm in just the last century.
Since then, greenhouse gas emissions have accelerated as cars and power plants became more common. This has added to the concentration of CO2 in the atmosphere and sped up the rate at which the Earth’s temperature has been warming.
As a result, temperatures have already risen by about 1.2 degrees Fahrenheit (2.2 degrees Celsius) since 1880, with the biggest changes happening in the past two decades. Warmer temperatures mean greater frequency of extreme weather events and higher risk of flooding and drought.
Scientists have also shown that the impacts of climate change are already being felt by the people and communities that are most vulnerable to it, including some of the world’s poorest countries. As temperatures increase and droughts and floods become more frequent, people with lower incomes, often in rural areas and developing nations, are more likely to lose their livelihoods and to be exposed to dangerous conditions.
Some people are more sensitive to these stresses than others, but most can adapt and live with them. For example, older adults are less susceptible to extreme heat than younger people, so they can live with and adjust to the new normal without being exposed to dangerous levels of exposure.
Other ways that people are affected by the climate change crisis include rising sea levels, more severe droughts, and a rise in the frequency and severity of heat waves and other extreme weather events. Many of these impacts are already causing millions of dollars in damages each year, and many more are on the way.
The cost of the consequences of climate change is growing fast, and will continue to mount as the climate continues to shift. This is why scientists are urgently trying to slow greenhouse gas emissions and put a lid on future climate changes.
Almost all the long-term warming that has occurred can be traced to greenhouse gas emissions and other human activities. These are offset by cooling from other factors, including atmospheric aerosols from burning fossil fuels and short-lived emissions of ozone gases.