Climate Change is a long-term average change in the Earth’s atmosphere and surface temperatures caused by human activities. It is an important factor in the Earth’s energy balance, affecting all parts of our planet and influencing global weather patterns. This is a complex topic, but scientists have found that changes to the concentrations of greenhouse gases in the atmosphere are the main cause of climate change.
Human activities include the burning of fossil fuels (coal, oil and gas) and land-use changes. These activities add large amounts of carbon dioxide and other greenhouse gases to the atmosphere. Those gases act like a blanket around the Earth and trap heat from the Sun. As the blanket warms up, ocean and air temperatures rise. Ice sheets melt and sea levels rise. Some animals may find it harder to survive as they move to new habitats and other species may die out entirely.
These changes have been happening for decades. The last few years have been the warmest on record. Scientists can measure the amount of greenhouse gases in the atmosphere, and they have been getting higher and higher. In fact, it’s so high that we can’t remember a time when the atmospheric concentration of CO2 was this high.
It is impossible to predict exactly what will happen in the future. However, the CMIP5 models, or Representative Concentration Pathways, have shown that the planet is likely to continue warming over the next few decades to centuries with no significant reduction in emissions.
Other factors that can affect the climate system over a few days to a few years include solar activity and volcanic eruptions, which can increase or decrease the amount of small particles in the atmosphere, reflecting or absorbing sunlight. These effects vary from place to place and from year to year.
Scientists can also track the history of climate change by studying tree rings and other climatological data, such as changes in snowfall or wind speed. They can compare these to records of natural climate phenomena, such as the El Nino Southern Oscillation in the equatorial Pacific.
There are many reasons to stop climate change. It is harmful for people, ecosystems and economies. It can lead to food and water shortages. It can cause conflict over resources and drive people to migrate. It can damage marine ecosystems by increasing ocean temperatures and acidity, decreasing oxygen levels, and causing coral bleaching.
The impact of climate change will differ across regions and sectors, and will be felt more strongly in some places than others. Less developed countries may be more affected than industrialized ones. If less developed countries feel disproportionately hurt by climate change, they could form a political backlash against the world’s leading carbon emitters, including the United States. Climate change also raises the risk of flooding in some parts of the world, threatening low-lying areas and coastal ecosystems. It can also make sea levels rise, putting many cities at risk of being submerged in the future.