One of the items that was briefly mentioned in the post Complexities and Realities was ‘Tipping Points’. In this post we discuss that topic in greater detail.
Climate change tipping points refer to critical thresholds or points at which relatively small changes in environmental conditions can lead to abrupt and irreversible shifts in the state of a system. Once a system has passed a tipping point it will not return to the previous condition, at least on a human time scale. The key words are abrupt and irreversible. Crossing a tipping point may also create feedback loops in other systems that affect the climate.
Predicting changes to the climate is very difficult ― the system is so complex, and there are so many feedback loops ― many of which are not fully understood. However, predicting tipping points is even more difficult due to their abrupt nature. This may be the reason that formal reports from organizations such as the IPCC (the Intergovernmental Panel on Climate Change) underestimate the speed with which the climate is changing.
Examples of climate change tipping points include:
Melting Ice Sheets
Ice sheets in Greenland and the Antarctic are melting quite rapidly as a result of increased ocean and atmospheric temperatures. This process is likely to accelerate due to the albedo or ‘Blue Ocean’ effect. Ice reflects the sun’s rays, whereas water, which is dark in color, absorbs that energy.
Disruption of Ocean Circulation
Changes in temperature and salinity are already changing ocean circulation patterns such as the Atlantic Meridional Overturning Circulation (AMOC), potentially leading to significant shifts in regional climates and weather patterns. These changes could lead to sudden changes in the climate (for example, the weather in Europe may become colder). Once more, these changes could occur quite quickly and are irreversible.
Release of Methane from Permafrost
Permafrost contains vast amounts of organic matter that can release methane, a potent greenhouse gas, when it thaws. The permafrost may be on land ― particularly in Canada and Siberia ― or they may be on the floor of the ocean. As temperatures rise, this process could accelerate, leading to further warming and exacerbating climate change.
Loss of the Amazon Rainforest
Increased temperatures and changes in precipitation patterns. These changes could transform the forest from a carbon sink to a source of increased CO2 emissions.
