What are the Dangers?

21st century ecological sensivity map by NASA

Continuing climate change will see an increase in wildfires, longer periods of drought and tropical storms that be stronger and last longer. Glaciers are already getting smaller, and ice is melting faster than previous records which impact on the habitats of plants, animals and humans across the globe.

In May 2019, sensors tracking the Earth’s atmospheric concentration of CO2 since the late 1950s detected the highest-level CO2 concentration of 415.26 ppm recorded for three million years when sea levels were several metres higher, and trees grew at the South Pole. Scientists have warned that carbon dioxide levels higher than 450ppm are likely to lock in catastrophic and irreversible changes in the climate.

Intergovernmental Panel on Climate Change

The renowned worldwide Intergovernmental Panel on Climate Change (IPCC), predicts a temperature rise of 1.4 to 5.5 Celsius (2.5 to 10F) over the next 100 years as greenhouse gases are unlikely to fall to zero due to the actions of humans.

Future Effects

Climate change is dangerous, though the effects will vary by region. Our world is already about one degree Celsius hotter than in the “pre-industrial” period in the mid-nineteenth century, and it is certain to become increasingly warmer into the next century.

Frost-free/growing season will be longer

The Earth has been witnessing a longer frost-free season over the last 30 years, affecting ecosystems. Plants are able to grow in new regions at the same time as becoming extinct in others. As the climate warms, the growing season could increase by a month or more by the year 2100 and are forecast to be up to eight weeks at higher elevations or on the coast.

Rainfall pattern changes

Average rainfall has changed over the last 120 years. Compared with temperature trends, changes in rainfall patterns are harder to predict, with the dangers to some areas still uncertain. What is known, is that changes in rainfall impacts on the runoff to rivers, with a one per cent change in rainfall having a two to three per cent change in the runoff. In addition, as the warmer climate intensify tropical cyclones over most continents. A heavy rainfall event that currently occurs only once in 20 years is expected to occur at least twice as often by the end of the 21st century.

More droughts and heat waves

lthough there is wide regional variability, a warmer future will probably lead to more intense and frequent rainfall interspersed with longer periods of abnormally hot weather. Meanwhile, cold waves will become less intense across the entire planet, a trend that has been accelerating since 1970. Higher summer temperatures will reduce soil moisture which intensifies heat waves. Drier weather means that some forests are no longer recovering from wildfires and animals are finding it increasingly difficult to find a hospitable wildlife habitat.

Hurricanes will be more intense

The world has witnessed some of the most intense hurricanes in the last couple of decades, with more frequent Category 4 and 5 hurricanes. While wind speeds are unchanged, increased rainfall of between five and ten per cent has been recorded. Storms are expected to intensify as the amount of water vapour in the atmosphere rises. An increase in rainfall will likely breach stormwater systems in urban areas, as already witnessed with Hurricane Katrina in the US in 2005.

Sea level will rise

The global sea level is now 200mm higher than in 1880 when reliable record-keeping began. Scientists forecast a rise of another three millimetres annually, adding another 1220mm by 2100. The increased water will come from melting land ice and the expansion of warmer seawater.

The number of storm surges and high tides are also expected to rise, which increases the danger of flooding in island nations and coastal regions. As the oceans take a long time to respond to warmer conditions, the sea level is predicted to continue rising into the next century at rates similar to those being seen now, or possibly higher. Add in land subsidence due to underground water supplies being drained away to meet water needs, and the impact of rising sea levels are already catastrophic in some parts of the world, with discussions about how to protect coastal communities from rising sea levels, including how to decide which to save first.

The Arctic will probably become ice-free

During the summer months, the Arctic Ocean is expected to become ice-free at some point within the next thirty years. The addition of water to the ocean from loss of ice from glaciers will cause the sea level to rise. Since 1990, there have been further contributions to rising sea levels from surface melting of the Greenland ice sheet, with more ice melting into the ocean from the Antarctic ice sheets.

Socio-political effects

Climate change is also having economic and socio-political effects and has been a central concern of policymakers, individuals and communities. Understanding the dangers of climate change has to be matched with a coping response and plans for recovery after any disruptive event. Food security is already being impacted in a number of African countries, with poorer countries less well equipped to manage rapid change and likely to suffer the most. In addition, researchers are studying the correlation between climate change and an increased likelihood of military conflict. The World Health Organisation has warned that the health of millions could be threatened by increases in malaria, water-borne disease and malnutrition.