One of the biggest problems our Earth is facing today is global warming. Even many people doubt that global warming exist, probably everyone noticed that there have been changes in the weather since we were children. Me too, even my childhood was not very long time ago.
But what is it global warming? Usually we use this term to describe a gradual increase in the average temperature of Earth´ s surface, oceans and atmosphere. Over the past 50 years the average global temperature has increased at the fastest rate in recorded history. And it is accelerating. All but one of the 16 hottest years in NASA´ s 134-year record have occurred since 2000. According the Environmental Protection Agency, Earth ´s average temperature has risen by 0,8 degrees Celsius over the past century. And to future, it is projected the rise of the temperature from 1,13 to 6,4 degrees Celsius.
What are the causes of global warming? It can be also caused by changes in nature (like it is often presented by some politicians), but big majority of climate scientists agree that the rate of global warming trends the planet is now experiencing is primarily the result of human activity. Global warming occurs when carbon dioxide, methane and other air pollutants (known as greenhouse gasses) collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the Earth´ s surface. This radiation would normally escape into space, but these pollutants trap the heat and cause the planet to get hotter. This phenomenon is known as greenhouse effect.
The effects of global warming are already visible. The huge icebergs melt, the storms are more aggressive. And this is just the beginning. The scientists believe that climate change will make hurricanes more intense (we could saw it also in the past few years). It is because their energy comes from temperature differences between the warm tropical ocean and cold upper atmosphere and global warming increases this difference. Of course, temperatures are getting more intense, as well.
The fact that many people do not link with global warming is, that it can cause the cooling of some parts of Earth, mainly Europe. It is called climate paradox. How is it possible? There has been a study made in 2015 that analysed winter weather data between 1958 and 2014. The scientists found out that over the past years, ice levels in the Icelandic and Greenland seas (regions that are important regulators of Earth´ s climate system) have significantly reduced. That´s why they believe, that this loss of ice will cause the flow of warmer water from the tropics to be affected, weakening the Gulf Stream and leading to cooler temperatures in Western Europe.
The research, that was published in Nature Climate Change, is the first attempt to examine how changes in the air-sea heat exchange in the region can affect global warming. This is also the first research where scientists have considered the possible impact of these changes on oceanic circulation, including the Atlantic Meridional Overturning Circulation (AMOC).
AMOC is a process in Atlantic Ocean, when warm, salty water travels north in the upper layers of the Atlantic, while a colder flow of water moves south in the deep Atlantic. It moves a large amount of heat energy from the tropics to North Atlantic. This heat is then transferred to the atmosphere and moderates the climate in this region. As the heat is transferred, the water becomes colder and denser and this sinks and travels back to the south and eventually rises again in the tropics.
The problem is, that as sea ice from Iceland and Greenland retreats, this flow of cold water to the bottom of the North Atlantic Ocean could be reduced, and therefore weaken the warming effects of the Gulf stream. And that could cool the atmosphere over the British Isles and western Europe. The result of this phenomenon in the medium term would be a slight cooling in average temperatures, cooler summers and less rainfall.
This is predicted to be one of the irreversible tipping points that could result in calamitous climate change. Besides Europe, this can have also negative effects for the North-eastern United States (like more summer rainfall).
According to another study, some scientists think that this phenomenon will cause a slowdown of the Thermohaline Circulation, rather than cooling Europe. That would mean that the continent will still warm, but less quickly than other parts of the world. This new situation could rise the welfare in Europe, because other parts of the world will warn faster. The study also predicts that developing countries may warm faster than other, more developed parts of the world.
There are also scientists that do not believe the Gulf stream has so large impact on the climate in Europe. They think the role of ocean heat transport in determining regional climates around the Atlantic Ocean is limited and the atmospheric flow of heat has a major influence on climate in North Atlantic region. According to their study, a slowdown of the Gulf Stream would cause a modest cooling tendency. This would not change the contrast across the Atlantic and not put Europe back into the ice age or anything like it. In fact, the cooling tendency would probably be overwhelmed by the direct radiatively-driven warming by rising greenhouse gases. They even compare this “European climate myth” to myths like Earth being flat and sun going around the Earth.
The opinions of scientists on causes of global warming in Europe are different. There are also researches made to support their arguments. Some of them think the global warming can cause the cooling of Europe, some of them do not think so. The fact is, that even if it didn´ t cause cooling of Europe, it will have some consequences, more likely negative. That means, no matter of cooling or warming, we must stop it in order to maintain the climate we are used to now. Not just to save Europe, but to save the whole world.
Governments need to jointly decide to dramatically reduce greenhouse gas emission by switching to renewable sources of energy. But we, as individuals can contribute to this too in our everyday life. We can use more energy efficient appliances, use less hot water, recycle, use reusable bags, buy fresh locally grown and produced foods. Also, we could reduce the number of miles we drive by walking, biking, taking mass transit whenever possible. It is all on us, we can stop it, but we need to cooperate and change our way of life unless it´s too late.
Lucia Poláková
Sources:
http://climatenewsnetwork.net/global-warming-threatens-colder-climate-for-europe/
http://www.iflscience.com/environment/global-warming-could-lead-european-cooling/
http://www.wired.co.uk/article/met-office-hottest-two-years
https://www.sciencedaily.com/releases/2016/07/160711100940.htm
http://ocp.ldeo.columbia.edu/res/div/ocp/gs/
Environmental Issues at Faculty of International Relations 