Warming to Climate Change
The terms Climate Change and Global Warming are now terms that we hear almost daily and are now very familiar with, but let’s look more closely at how these phenomena affect us and the planet we live on.
Global warming is being caused in the main, by human activity releasing gases like carbon dioxide, methane, nitrous oxide and water vapour into the atmosphere, all of which boost the harmful effect of heat from the sun’s UV (ultra violet) rays. These are referred to as ‘greenhouse’ gases as they have a similar effect on the earth’s atmosphere as a greenhouse would have on the air surrounding the plants in it.
The Earth’s atmosphere is about 1.1°C warmer than it was in the 1800s and current trends do not meet the Paris Agreement target of capping global temperature rises at 1.5°C, which is considered to be the upper limit to avoid even worse damage to the planet from climate change. These temperature rises may seem almost negligible but they are already causing major changes in our climate. These changes are not uniform across the globe; some regions are faced with severe droughts while others are being hit by torrential rain causing catastrophic floods.
A temperature rise in the earth’s atmosphere of 1.5°C, may appear to be very small, but small rises in temperature lead to big changes for the world’s climate. This is because the amount of extra energy needed to increase the world’s temperature, even by a little, is vast. It should be said at this point that a 1.5°C increase in the temperature of the earth’s atmosphere does not mean a 1.5°C in our weather patterns. This year in the UK we have seen record surface temperatures up to and in excess of 40°C, when temperatures in the mid to high twenties would normally be expected. Global surface temperature has increased more since 1970 than in any other period over at least the last 2000 years, while 2015-2019 were the warmest years on record, with the last decade the warmest decade on record. As global warming persists, these temperatures will continue to rise.
Increased surface temperatures are not just uncomfortable for most of us, they cause severe medical problems in people with issues such as heart disease, cardiovascular problems or asthma. The most vulnerable to these higher temperatures are children, the elderly, the poor, and those with underlying health conditions. Changes in climate also contribute to the spread of tropical diseases such as malaria and cholera as well as malnutrition caused by crop failure and drought.
Due to the changing climate, many regions are experiencing more frequent and longer lasting droughts, caused by the combination of lack of rain and surface water evaporation caused by the higher temperatures. The results of these droughts can be seen in disruption, if not failure of many crops, which in turn causes food shortages and the inevitable problems of malnutrition and starvation in many of the hardest hit regions.
Conversely, global warming also increases water vapour in the atmosphere, due to surface water evaporation, over both land and sea, which can lead to more frequent and sustained heavy rain. This can lead to major flooding over wider areas as rivers overflow in low lying areas and drains in urban areas fail to cope with the increased volumes of rain water. Flash floods and landslides will also become a more regular phenomena.
It seems strange when news reports from around the world highlight major flooding and the devastation caused to one country and at the same time show huge areas of other countries suffering from severe drought and the attendant threat to health and life from lack of food and clean drinking water.
A warmer atmosphere over the oceans will increase water vapour over the sea as a result of increased evaporation of surface water makes it likely that storms and hurricanes will become more intense, produce more rainfall, and develop more readily from category 3 to category 4 hurricanes.
In addition, global warming is causing sea levels to rise. Sea water expands as it warms, which increases the amount of seawater that is pushed on to shore during coastal storms. That extra seawater, along with the increased rainfall, will increase the occurrence of destructive coastal flooding and potentially increase the effect of tidal damage caused to coastal areas by hurricanes.
The rise in sea levels is also being accelerated by the melting of polar ice and glaciers. Polar ice caps are melting due to global warming, with Arctic sea ice presently disappearing at a rate of almost 13% in the past decade. However, as well as adding to the rise in sea levels, the bright surfaces of polar snow and ice reflect the heat of the sun rather than absorbing it, but less ice means less reflected heat and more heat being absorbed, which would mean higher temperatures worldwide. It could also mean more extreme winters: as the polar jet stream is disrupted by warmer air, it can dip south, bringing bitterly cold air with it. We are also seeing a decline in populations of polar species such as polar bears, penguins, walruses, arctic foxes, reindeer, and many other species as their habitat is slowly but surely disappearing.
Arctic ice and permafrost, which is ground that is permanently frozen, store large amounts of methane which is a greenhouse gas and major contributor to climate change. As that thaws, the methane will be released, which in turn will increase the rate of global warming.
The same is true of deforestation, either as a result of massive areas of forest being cut down or because of wild forest fires caused by warm, dry timber catching fire during prolonged heatwaves. Trees and vegetation store carbon monoxide but as they are felled, or the wild fires consume them, that greenhouse gas is released into the atmosphere, accelerating the global warming process
As with many changes to the environment caused by global warming, the effects of that change are not limited to that region but have an effect across the planet, hence the phrase ‘global’ warming.
Thousands of people have been killed in climate catastrophes, such as floods, hurricanes, or as a result of drought. Millions of pounds have been spent on reconstruction of weather related damage to homes and infrastructure. Climate change affect not only humans, many animal, bird and insect species are also affected by climate change as their habitats change or in some cases disappear and they struggle to adapt.
The Paris Agreement, adopted in November 2015, sets out a global framework in an attempt to peg back climate change by limiting global warming to a maximum of 2°C with an aim of limiting it to 1.5°C. The Agreement also aims to help vulnerable countries, such as small low lying islands or countries prone to extensive flooding to deal with the impacts of climate change and support them in their efforts to overcome their climate related issues.
If we were to do nothing to reduce our carbon emissions, global temperatures could increase by as much as 4.4°C by the end of the century, which considering the present 1.1°C rise in temperature and attendant changes to our climate, would have a catastrophic effect on the planet. To comply with the Paris Agreement, carbon emissions need to be reduced by 45% by 2030 and reach net zero by 2050. As things stand at the moment, we will not reach these targets.