The discussion about climate change often focuses on keeping the average global temperature increase to 2-6 degrees Celsius. This is just a small part of the impact – local temperatures could rise much more. In addition, air and water currents could change to the extent that it would have a substantial impact on various ecosystems.
Summary of the consequences (IPCC)
Climate change in the last century has had worldwide repercussions. More than 95% of the observed changes are consistent with the expected responses to climate change. These are some of the IPCC predictions of the consequences of climate change and what it will mean for humans:
Extreme changes
- Tropical cyclones, storms
Casualties and damage by flooding and wind, economic losses in transport, tourism, infrastructure and insurance - Extreme rainfall, rivers overflowing
Erosion, earthquakes, flooding, damage to settlements, transportation systems and infrastructure - Heat or cold waves
Effects on human health, social stability; demand for energy, water and other services (e.g., water or food storage), infrastructure (e.g., energy transport) - Drought
Availability of water, subsistence, energy production, migration, transport via waterways
Average changes
- Temperature
Demand for and price of energy, urban air quality, thawing of the permafrost, changes to tourism and recreation, consumption, subsistence, loss of melt water - Precipitation
Subsistence, salinization, tourism, water infrastructure, energy supply - Sea level rise
Loss of use of coastal areas, risk of flooding, water infrastructure
Other consequences described by the KNMI
We will probably get more frequent extreme weather conditions. Worldwide, there are more and more areas facing flooding, heavy rainfall and periods of drought. An article in the scientific journal Science (2011) showed that the chance of summer mega-heat waves in Europe may increase by a factor of 5 to 10 in the next 40 years. The hottest summers in Europe in the last decade were significantly warmer than the summers in every decade since the year 1500. The heat wave in 2010 surpassed all others in intensity and spatial extent. Moscow hit a high of 38.2 degrees Celsius.
Sea level
Another consequence of global warming is the rise in sea level. In the 20th century, there was a rise of about 14-20 centimetres. This means a rise of 1.4-2.0 millimetres per year. In recent years it has gone increasingly faster. Satellite measurements have shown a rise of about 3 millimetres per year between 1993 and 2005. Because the time period is relatively short, it is still unclear if this is due to climate change or to natural fluctuations in sea level and changes in ocean currents. What we do know is that the rising sea level will continue and accelerate in the long term. In the KNMI’s climate scenarios, the sea level rise along the Dutch coast is assumed to be 15-35 centimetres by 2050.
Ice caps
The rise of the sea level is in part due to the melting of the ice caps. A study published in 2011 in the scientific journal Geophysical Research Letters showed that the ice was melting faster in Antarctica and Greenland. In the last 18 years, the melt rate of the ice has increased by an average of 26 gigatonnes per year. Currently, it is at more than 500 gigatonnes annually. This corresponds to a 1.4 millimetre sea level rise per year. In 2011, the amount of sea ice around the North Pole reached a record low. The lowest volume of sea ice was more than 70 percent under the volume measured in 1979 and 1980.
Nature
Nature will also feel the effects of climate change. Because of the rising temperatures, plants and animals will migrate towards to poles and up elevations. The winters will grow shorter and the growing season longer. The last ten years have seen a growing season an average of a month longer than in the previous century.
Tipping points
It is also possible that we will have to deal with surprises (‘tipping points’). Tipping points are processes that unexpectedly accelerate climate change. One example could be the cessation of the warm Gulf Stream, which would make it colder in Europe. It is certain that the flow of ocean currents can change when the temperature of seawater rises. It is not possible to predict when this will happen using our present models. If this happens, local temperatures could change much more quickly than the current variations.
Sources: IPCC and KNMI
The IPCC, the Intergovernmental Panel on Climate Change, is a United Nations organization established in 1988 to evaluate the risks of climate change. The panel consists of hundreds of experts from around the world, from universities, research centres, businesses, environmental groups and other organizations.
The KNMI is the Dutch national institute for weather, climate and seismology. The KNMI provides weather information to improve the safety, economy and sustainable environment for the general public, the government, aviation and shipping. For long-term developments, the KNMI does research into changes in the climate.
