Basic Climate Change and Human Impact on Health
When we talk about climate change, we’re generally talking about human-caused changes in the weather rather than natural changes that occur over time. Changing climates can have a wide range of effects on people and the environment. People of color and those in disadvantaged socio-economic groups tend to experience the worst effects.
Human-caused climate change
Human-caused climate change is changing the global climate, disrupting communities and ecosystems. It is already increasing the risk of heat-related deaths and other illnesses, and adding more hazards. In addition to increasing the severity of weather events, climate change is expected to damage critical infrastructure and cause economic disruption. This, in turn, is likely to lead to increased migration and social unrest.
The increase in greenhouse gases, particularly carbon dioxide, has many effects. It intensifies the greenhouse effect, a natural phenomenon that causes the temperature of Earth’s atmosphere to rise. Scientists have proven this in laboratory experiments.
Natural climate change
Although the Earth’s climate has always been subject to change, the rate of this change is alarming. The increase in greenhouse gases since the Industrial Revolution has increased the amount of heat that our atmosphere holds. This increased heat has a negative impact on Earth’s surface temperatures. Aerosols in the atmosphere also alter the climate, because they absorb solar radiation and scatter it. These changes can affect weather patterns and human health.
Models of climate change take both natural and human forcings into account. For instance, the carbon dioxide (CO2) from the atmosphere acts as a greenhouse gas and traps incoming heat. In addition, aerosols reflect sunlight and influence cloud formation. Both of these affect temperature, and their contributions are estimated by a regression model. The climate model is based on the IPCC (2013) standard simple climate model. It is estimated by fitting the observations to these forcings.
Extreme weather events caused by climate change
Scientists are starting to tie the occurrence of extreme weather events to the increase of greenhouse gases in the atmosphere. Increasing amounts of these gases are causing the global mean temperature to rise. Daily temperature data is also pointing to an increased incidence of extreme heat events. Furthermore, a study of individual heat waves shows that the probability of an extreme event is increasing.
Fortunately, scientists are getting better at analyzing the causes of extreme weather events. The Bulletin of the American Meteorological Society publishes research on these events. Extreme events have increased in frequency and severity over the past decade or so, and human-induced climate change has made them more likely. However, natural variability is always present and is not solely responsible for extreme weather.
Models that estimate impacts of climate change on health
There are two main approaches for estimating the impacts of climate change on health. The bottom-up approach focuses on developing damage functions that are specific to different regions, and the top-down approach focuses on global scale effects. Both approaches use epidemiological and econometric data to derive health-related impacts. The bottom-up approach is more complex and can simulate higher levels of local-scale complexity, such as the effects of biophysical and behavioral adaptations. It is, however, limited by the availability of spatially-resolved data.
To address this challenge, the group of 26 health experts met virtually in May 2021 to review the relevant literature and formulate recommendations for improving health models used in economic-climate models. The group formed four subpanels to review relevant literature and discuss key issues related to the development of health damage modules.
Adaptation planning
Adaptation planning involves preparing for and responding to changes in climate and the impacts of these changes. Its purpose is to minimize risks associated with climate change, such as sea-level rise and more intense extreme weather events. It can also help make the most of benefits associated with climate change, such as longer growing seasons.
Many ecosystems and species are at risk of extinction due to climate change, and many people rely on these resources. For example, climate change is predicted to expand the range of Californian almonds, despite recent years of drought. This trend is especially hard on small farmers.
