Climate Change is a global phenomenon with significant and often unpredictable impacts on people, natural and built environments, and the economy. It’s the result of human activities, including land use and energy production, that contribute to the build-up of greenhouse gases in Earth’s atmosphere, such as carbon dioxide (CO2). These gases act a bit like the glass in a greenhouse, trapping some of the sun’s heat and stopping it from escaping back into space, thus warming the planet. The CO2 concentration in the atmosphere is now at its highest level in the history of human civilization, having increased by 48% since pre-industrial times.
Warmer air can hold more water vapor, so climate change is associated with more floods and droughts. It’s also leading to higher sea levels threatening coastal ecosystems and low-lying cities. Warming is especially pronounced in the Arctic where it’s already causing the loss of Arctic ice sheets and a decrease in winter snow cover.
As temperatures rise, habitats are losing their diversity and species are disappearing. In the long term, this could cause a significant loss of biodiversity, affecting our food and water supply. It is also expected to impact ecosystems that provide us with important services, such as pollination or water purification.
Some living things may be able to adapt to climate change, for example plants growing faster or species expanding their geographic range. However, many species are being pushed to the edge of survival as their natural habitats are altered. In addition, invasive species, such as lionfish and ticks, are becoming more common in warmer areas.
Changing weather patterns will affect every region and have profound effects for many societies. The economically disadvantaged and people of color, who have contributed the least to climate change, will be the most affected by its worst impacts.
In the short term, climate change will be experienced in the form of warmer temperatures and longer periods of dryness, with some regions experiencing extreme temperature increases. Climate changes are already being felt by many people around the world, for example, by record-breaking heatwaves and more frequent and intense flooding.
Scientists are working hard to understand and communicate the risks associated with climate change. There is a wide international consensus that climate change is happening and that it is mostly man-made. The IPCC’s Fifth Assessment Report, published in 2014, shows that the consequences of global warming will be severe for the people and nature on our planet. Limiting global warming to 1.5degC will require “rapid and far-reaching” transitions in the ways we produce, consume and manage our energy, land and buildings. It will also require cutting global net human-caused emissions of carbon dioxide to near zero by 2050. This is an ambitious but necessary goal. It’s the only way we can protect our home, the Earth. The future of our children and grandchildren depends on it.