The Effects of Climate Change

Climate Science Series

In the previous article from the climate change series, we explained the meanings behind the terms climate change, global warming, the greenhouse effect and greenhouse gases. We also briefly mentioned what are the effects of climate change that we observe. Today we will give more information on what we can expect for the future and what the other effects are that are being observed which point to this phenomenon.

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Present Effects

As mentioned in the previous article, the main consequence of global warming is the increase in Earth’s average temperature. Since the late 19th century, Earth’s temperature has increased by around 0.9 degrees C (1.62 degrees F). This may not seem like a large amount but even a small increase in the global average temperature can have huge impacts on the climate as a whole.

Since 7/10 of the Earth’s surface is covered in water, the ocean has absorbed most of this heat, causing the sea temperature to rise. This has devastating impacts on marine life and is causing coral to bleach, which if not rectified, will kill a huge amount of coral across the globe.

Rising sea temperatures also cause the ice at the poles to melt. While the polar ice caps do undergo phases of melting and freezing in summer and winter, the gradual increase in sea temperature has meant that the size of the ice caps in winter are shrinking each year. In fact, it is estimated that Antarctica loses around 127 billion tonnes of ice per year  (1 tonne is 1000kg).

The oceans also absorb CO2 released from burning fossil fuels. When CO2 is dissolved in water it is acidic. Therefore, the acidity of the sea is increasing which can also devastate marine ecosystems and put marine life at risk.

Across the globe, the amount of ice and snow is depleting each year with glaciers shrinking and snow cover decreasing. In addition, the snow begins to melt earlier in the season.

The mass of ice from the polar ice caps and snow cover and glaciers has to end up somewhere. The mass of all that water is deposited in the sea, causing the global sea level to rise. In the last century, sea level has grown by around 8 inches. The rate of the rise accelerates each year.

As mentioned in the previous article, global warming can also cause more frequent extreme weather events. This is because the temperature has a huge impact on how extreme weather events such as tornadoes and hurricanes form.

Finally, global warming has an effect on animal and plant behaviour. The time of year when plants and flowers bloom has changed and other seasonal animal behaviours have similarly shifted. Since plants and animals use the temperature as an indication of the time of year this can have a significant impact on the life of the organisms and the ecosystems as a whole.

Predicted Future Effects

These effects have already had a significant impact on agriculture, industry and both land and marine ecosystems. It seems if nothing is done these impacts will continue for the remainder of the century and beyond.

If the release of CO2 is continued, global temperatures will continue to rise at an accelerating rate.

The growing season or the time of year when crops are growing will lengthen.

Rainfall will in general increase and heavy rainfall events or heavy precipitation events will become more frequent. So get the umbrella ready!

Despite general rainfall increasing there will also be more droughts and heat waves.

The hurricanes will be more frequent and more intense.

By 2100 the sea level is expected to rise by between 30 and 120 cm (1 and 4 feet). This would also increase the likelihood of flooding.

In the summer before the middle of the century, the Arctic is expected to be essentially ice-free.

Next up: Renewable Energy

Sources

  1. Image – Polar bear – source NASA; credit Mario Hoppmann – https://climate.nasa.gov/news/2499/polar-bears-across-the-arctic-face-shorter-sea-ice-season/
  2. https://climate.nasa.gov
  3. https://oceanservice.noaa.gov/facts/coral_bleach.html

What is Climate Change?

Climate Science Series

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By now you have probably heard the terms climate change and global warming thrown around and heard from people who are adamant they are happening and those who are adamant that they aren’t. However, what do these terms really mean? How do we know if they are happening or not? In these journals, we are going to explain all the jargon surrounding this topic and hopefully make the subject much clearer. We’ll also let you know what you can do to fight climate change because every individual’s contribution can make a difference.

Global Warming

The term global warming refers simply to the warming of the Earth over the past century. Since the early 20th century the average temperature of the Earth’s surface and atmosphere has increased. This temperature is calculated by measuring the temperature across the entire globe during the year so seasonal changes and differences between local climates do not affect the results.

The results show unequivocally that the Earth is heating up. Although it may not always seem like it. The term global warming makes us picture warmer summers, more sunshine and less harsh winters. However, the effects of a heating planet are not as pleasant as it may seem.

Climate Change

The other term you hear floating around is climate change. This is often used interchangeably with the term global warming but in fact, there are subtle differences between the two.

While global warming refers purely to the heating of the Earth, climate change refers to the many changes in the climate that occur as a result of the heating of the Earth. This can be an increase in rainfall, more frequent extreme weather events, melting polar ice caps and many other impacts on the Earth’s climate.

The term climate on its own refers to the weather patterns of a particular location. For example, the Sahara desert has a very dry and hot climate and the climate of the UK is wet and moderate. Over the past few decades, we have noticed more extreme weather events such as hurricanes, smaller polar ice caps and shifts in the blooming of plants and flowers. These events are all due purely to the increase in Earth’s average temperature.

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Graph showing the increase in CO2 levels since the industrial revolution. Credit NASA and Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record

The Greenhouse Effect

Why is the Earth’s temperature rising?  And how do we know that we are responsible for it?

The Earth’s atmosphere is responsible for controlling the temperature of the Earth and at the Earth’s surface. The atmosphere contains many gases which warm up the Earth in a process known as the greenhouse effect. If you have ever been inside a greenhouse you’ll know that inside it is much warmer than outside. This is because the glass is able to allow sunlight to pass into the greenhouse but traps the heat from the sun inside, warming up the plants.

The Earth’s atmosphere acts in a similar way. Light from the sun passes through the atmosphere and the heat generated radiates from the Earth’s surface. The gases in the Earth’s atmosphere trap this heat and reflect it back to Earth, thereby increasing the global temperature. The gases that cause this effect are known as greenhouse gases.

Without this phenomenon, the Earth would be too cold to be habitable. However, the effect is causing dramatic changes in climate that we are noticing today.

Greenhouse Gases

The major contributors to the greenhouse effect are water vapour, carbon dioxide (CO2), methane, nitrous oxide and chlorofluorocarbons (CFCs). Water vapour, CO2 and Methane are naturally present in the atmosphere whereas the presence of nitrous oxide and CFCs in the atmosphere are entirely due to human activity.

The reason that climate scientists believe that human activity is causing climate change is that the quantity of greenhouse gases in the atmosphere has increased over the past few decades. In particular, the proportion of CO2 has increased due to the emission of CO2 from the burning of fossil fuels and to a lesser extent – deforestation.

Summary

What we hope this article shows is that climate change is a real and measurable phenomenon that is irrefutable. Over the next few days, we will explain in more detail the evidence for man-made climate change and what can be done to stop it.

Next up: The Effects of Climate Change

Sources

  1. Image – Earth from Space – credit NASA; http://www.abc.net.au/science/articles/2014/09/05/4080293.htm
  2. https://climate.nasa.gov
  3. https://www.wwf.org.uk/climate-change-and-global-warming
  4. https://www.nationalgeographic.com/environment/global-warming/global-warming-overview/
  5. https://www.bbc.com/news/science-environment-24021772