Climate change is a problem that affects all people worldwide. It causes severe weather, strains agricultural systems, and makes entire regions less habitable. You've probably noticed weather patterns changing: Spring storms are more powerful, cities flood during high tides, and forests burn. Some coastal communities are even being relocated because the sea level is rising. These changes affect our quality of life and the way we live.
In recent years, scientists have been able to measure the rate at which sea levels are rising with the help of satellite measurements. The ice losses from the Greenland Ice Sheet and the Antarctic Ice Sheet have accelerated, causing sea levels to grow more quickly than in the past. However, there is a lot of uncertainty surrounding the rates of sea level rise. Researchers still need to understand the causes of sea level rise fully, but they have been able to reconstruct sea level changes that took place in the past.
The rising sea level is a significant concern for coastal life and ecosystems. It increases the intensity of storm surges, causing flooding and damaging coastal areas. It also affects freshwater resources and the bearing capacity of the ground.
Rapid greenhouse gas emissions have altered the conditions of the world's oceans at a rate not seen in millions of years. These changes have profound and irreversible effects on marine life and ecosystems. They result in lower ocean productivity, altered food web dynamics, and shifting distributions of species. In addition, these changes are threatening human food security.
Marine life is sensitive to changes in temperature and salinity. Even minor temperature increases can cause death in some species. Increased daytime temperatures may also decrease the diversity of rock pools, affecting an ecosystem's functioning. Increased salinity and temperature may also change the timing of reproduction, increasing the risk of mortality in these communities.
Sea level rise is a result of thermal expansion of water. While glaciers can balance the evaporation of seawater by generating snow, rising temperatures have caused glaciers to melt and sea levels to rise. In addition, the ocean's temperature has increased by approximately 1 degree Celsius since 1880, and this warm water absorbs about 90% of the extra heat caused by burning fossil fuels. The result is a rise in sea levels worldwide.
Rising ocean temperatures and sea levels may disrupt the ability of corals to build skeletons. Corals depend on calcium carbonate for their structure and are vulnerable to sea-level changes. Ocean acidification can reduce the calcium content of coral reefs, causing coral bleaching. Moreover, coral calcification has decreased by 14.2% in the Great Barrier Reef since 1990.
Climate change will affect human health in many ways, including direct impacts and indirect effects. The program at PAHO seeks to prepare health systems and decrease greenhouse gas emissions so that the health risks from climate change can be minimized. However, the effects of climate change on health will vary based on the type of climate change and the community's adaptation to it.
As the Earth's climate warms, the occurrence and severity of extreme events will increase, posing a greater risk to human health. Rising temperatures and rainfall patterns will increase the risk of food and water-borne illnesses. Increased rainfall and storms will cause more intense and widespread disease outbreaks. Climate change will also shift the geographic range of vectors that transmit diseases. These changes in weather patterns will expose more people to conditions that are spread through the bites of mosquitoes. As a result, the number of cases of West Nile, malaria, and other climate-sensitive health outcomes will increase.
Ocean warming is already affecting fish growth and migration patterns. In addition, it is changing the habitats of hundreds of marine species. Tuna, for example, are now migrating eastward, affecting the economies of Pacific Island nations.
Climate change affects air quality. Warmer temperatures and shifting weather patterns can worsen air quality, leading to respiratory health issues and asthma attacks. Climate change also increases the number of wildfires, which cause unhealthy air pollution. Additionally, rising carbon dioxide levels and warmer temperatures increase the amount of ragweed pollen in the air, increasing the risk of allergy attacks and other airborne illnesses.