In our previous article we discussed what climate change means in general terms, and we looked at the differences between climate change, global warming and weather. We are certain that the climate is changing yet the extent to which it will change is less known.

It is tempting to predict future climate change by extrapolating trends. Such extrapolation would be however only reasonable if previous and future climate changes had the same cause. In reality, anthropogenic (i.e. originating in human activity) climate change is the overall effect of several factors and the balance between them. It is the balance and ratio of different factors that differ between the past, present, and future.

We also know that climate changes naturally. Hence, climate variations during the past half-century represent a combination of anthropogenic change and natural variability. However, it is often difficult to separate these contributions from each other. Similarly, future climate changes will result from a combination of anthropogenic change and natural variability, but it is not known to what extend the natural variations will oppose or strengthen the anthropogenic changes.

Climate change impacts on humans and the natural habitats

It is important to consider how the changing climate will affect people across the globe as well as natural systems which we are part of. With temperature increase of 4°C, the risks become higher – climate change will have prevalent impacts on natural systems, significant species extinction, and it will pose large risks to food security. The IPCC report states that “Climate-change impacts are expected to exacerbate poverty in most developing countries and create new poverty pockets in countries with increasing inequality, in both developed and developing countries All aspects of food security will be potentially affected by climate change, including food access, utilization, and price stability.” Below we will analyze some impacts in more details.

Vulnerable societies

It is not surprising that climate change will affect people in an unequal way. People who are socially, economically, culturally, politically, or otherwise marginalized are particularly vulnerable to climate change. Risks are unevenly distributed and generally greater for disadvantaged people and communities given their limited capability to cope with the impacts and adaptation.

Threatened ecosystems

Some ecosystems are already at risk from climate change. The number of such systems at risk of severe consequences becomes higher with additional warming of around 1°C. There is a simple analogy to explain how significant an increase of one degree can be. Let’s compare the climate’s temperature increase to a child with a fever. It is not life-threatening. Nevertheless, it should not to be ignored. By 2050 some models estimate temperature increase of almost 4 °C – this temperature increase would be very serious for a child. This also marks the point at which climate scientists say irreversible changes would occur on Earth. By 2100, the rise could be up to 6 °C. Here, we are talking about an average, with the Arctic having the temperature increase doubled. So, like the child’s fever, the situation would become very critical. Many species and systems with limited adaptive capacity are subject to very high risks with additional warming of 2°C, particularly coral reef systems and already mentioned Arctic regions. Some species will adapt to new climates. However, those that cannot adapt fast enough will decrease in abundance or go extinct.

Extreme weather

Climate change with 1°C additional warming increases risks from extreme events, such as powerful storms heat waves, extreme precipitation, and coastal flooding. Risks associated with some types of extreme events increase further at higher temperatures. Due to sea-level rise projected throughout the 21st century, coastal systems and low-lying areas will increasingly experience adverse effects such as submergence, coastal flooding and erosion.

Human health, security & conflict

Projected climate change will impact human health mainly by worsening health problems that already exist. Local temperature and rainfall changes have altered the distribution of some water-borne illnesses. There are also risks associated with the increased number of parasites such as ticks that can carry Lyme disease. Increased temperature and humidity during their hibernation period enable ticks to thrive and increase their population. Changed climate is also expected to compromise normal human activities, including growing food or working outdoors. Climate change will increase displacement of people. The changes indirectly increase risks of violent conflicts in the form of civil war and conflicts emerging from poverty and economic shocks. The impacts of climate change on the critical infrastructure and territorial integrity are expected to influence national security policies.

What is next?

The changes will always be regional and will differ based on the location. In our next article we will discuss the climate change in Estonia and how it will affect the country’s population.