Research shows that human activity can lead to rising overall global temperatures, causing sea levels to rise, glaciers to melt, and creating frequent and extreme weather events like hurricanes, floods, and tsunamis. Changing climate affects the air we breathe, the safety of drinking water, food production, shelter for the more than half of the world’s population that lives within 37 miles of the sea or ocean, and loss of biodiversity. Further human actions such as deforestation, deep-ocean fishing, overharvesting of plant and animal species, as well as war and conflicts also contribute to biodiversity loss.

Fast Facts

  • Developing countries will be hit hardest by the effects of climate change—higher temperatures, changes in precipitation patterns, rising sea levels, and more frequent weather-related disasters—posing risks for agriculture, food, and water supplies.
  • Climate change is expected to threaten with extinction about one quarter of all species on land by the year 2050.
  • The world has warmed by approximately 33.5 °F in the last 130 years. Each of the last 3 decades has been successively warmer than any preceding decade since 1850.
In 2010, developed countries accounted for 18% of the population, 54% of GDP and 36% of global greenhouse gas emissions.


At the end of 2015, delegates from 195 countries met in Paris, France to negotiate the Paris Agreement, a global agreement to reduce greenhouse gas emissions and limit global warming to less than 2 °C (35.6 °F) compared to pre-industrial levels. For the agreement to become binding, 55 parties who produce over 55 percent of the world’s greenhouse gases had to have ratified the agreement. On October 5, 2016, the threshold for entry into force of the Paris Agreement was achieved and it will enter into force on November 4, 2016.