In the 21st century, people are concerned with many environment issues
One of the biggest problems is climate change, also called global warming. Scientists say Earth is getting warmer faster than ever before. Most experts say humans are causing this problem. Factories, cars, and other things we make release gases like carbon dioxide and other greenhouse gases. These gases trap heat in the air. As the oceans get warmer, glaciers melt and sea levels rise. This means less space for animals like polar bears to live. It also affects where people can live. Over time, global warming could hurt all living things on Earth.
In 2015, people from 195 countries met in Paris, France, for the United Nations Climate Change Conference. There, they worked out the Paris Agreement. The agreement was a global plan to reduce pollution. When enough countries approved the plan, it started in November 2016. To celebrate, Paris lit up the Eiffel Tower and Arc de Triomphe with green lights. Later, President Trump decided to take the United States out of this agreement.
