The Earth is 1 degree Celsius hotter than it was at the end of the 1800s and the amount of carbon dioxide in the atmosphere is higher than at any point in the past 2 million years. Carbon dioxide is a greenhouse gas that holds heat which causes the Earth’s average temperature to rise. Human health and well-being worldwide are impacted by a changing climate but some groups — socially and economically disadvantaged ones — face the greatest risks.
Climate change is causing heat waves, droughts, wildfire conditions, and extreme rainfall events around the world. It also impacts what crops we can grow and what animals we can raise, which disrupts food availability worldwide. But it’s not just humans feeling the impacts of a changing climate. Animals’ habitats and migration patterns are changing drastically as well.
Rising Seas
As temperatures heat up, seas begin to rise as warmer water expands due to a process called thermal expansion. “The Arctic is warming nearly four times faster than the rest of the world,” and melting glaciers and ice sheets compound the problem by releasing more and more water into the oceans. The rate of global sea level rise is now more than double what it was throughout most of the 20th century. These rising sea levels will continue to threaten low-lying areas, islands, and coastal populations, as well as contaminate aquifers and agricultural soils, erode shorelines and threaten ecosystems.
Ecosystems
Most plants and animals live in areas with very specific climate conditions, enabling them to survive and flourish. Any change in climate can impact the habitats of plants and animals and the ecosystems that they call home. For example, Arctic animals’ movement patterns are shifting in different ways as the climate changes. Although species are able to adapt to environmental changes given long periods of time, such a rapidly changing climate could require adaptation on a larger and faster scale than in the past. Polar bears, the North Atlantic cod, and the Quiver tree are all examples of species whose habitats are changing faster than they can adapt to new conditions. This could have far-reaching effects on many organisms through interconnected food webs and other interactions.
Agriculture
Climate change impacts all parts of agriculture and livestock farming. With an increase in temperature, some crops are no longer able to be grown in certain climates, while other crops may thrive with the increase of carbon dioxide in the atmosphere. Hotter and wetter climates may increase the growth of weeds and fungi, removing essential nutrients from the soil. Parasites may also thrive in hotter climates, harming agriculture and livestock. Fisheries could experience acidification from the increased amount of carbon dioxide, and the decrease of oxygen in their habitats could lead to dead zones.
Some countries may actually benefit from increased temperatures and changing levels of carbon dioxide. But climate change is expected to negatively affect crops, livestock, and fisheries in many regions, especially because of changes in the frequency and severity of droughts and floods. For example, California is expected to suffer from continued weather extremes, and corn crop yields are projected to decline by 24% as early as 2030. These changes in weather patterns will continue to put an extra burden on the global agricultural system, which is already struggling to respond to the increased demands for food.
Human Health and Environmental Justice
Climate change is a threat to everyone’s physical and mental health, access to clean air and water, and ability to seek out food and shelter. But some social and economically disadvantaged groups face much greater risks. Climate change is an environmental justice issue, and often those that emit the least amount of greenhouse gases are the most vulnerable to its impacts. Many of these communities have very few resources to help them adapt, receive the health care they need, or leave their homes if necessary.
For instance, sea level rise in Bangladesh will increase salinity in coastal areas, leading to shortages in drinking water and food availability, and malnutrition and water-borne diseases will likely follow. The impacts will fall disproportionately upon the poorest sectors of the population within all countries, which will intensify health inequities as well as access to sufficient food, clean water, and other resources.