Strong winds, heavy storms and floods in Europe. Hazardous winter conditions in the United States and extreme heat in Australia. These events seem to occur more often in the news and people are discussing it more than ever before. There is a growing awareness about the impact climate change has on weather patterns all over the world. However, being aware about something or having heard of something does not necessarily mean that someone fully understands what implications global warming has in the world or how it affects (or will affect) their daily lives. Therefore, this post will briefly focus on greenhouse gasses and will mainly focus on the altering jet stream.
The Greenhouse Effect
The term ‘Greenhouse Effect’ is commonly used to describe the increase in the Earth’s average temperature that has been recorded over the past 100 years. However, without the ‘natural greenhouse effect’, life on Earth would be very different to that seen today.
The Earth receives its life sustaining warmth from the Sun. On its way to the Earth’s surface most of the heat energy passes through the Earth’s atmosphere, while a smaller proportion is reflected back into space.
The energy warms the Earth’s surface, and as the temperature increases, the Earth radiates heat energy (infrared energy) back into the atmosphere. As this energy has a different wavelength to that coming from the sun, some is absorbed by gases in the atmosphere.
Most of the greenhouse gases occur naturally in the atmosphere. However, according to most mainstream scientists the increase in “greenhouse gases” is caused by human activities. (Source: BBC Weather Centre, July 2009)
The activities that contribute to global warming are:
The burning of coal for heat and electricity.
The burning of oil-based products such as: petrol, diesel and jet fuel in transportation.
The burning of coal, oil and natural gas in industrial activity. (OurChoice, Al Gore 2009)
Below: a vivid picture of what global warming is
The jet stream
A jet stream is defined as a narrow zone of high-speed winds. They can extend several thousand miles long. Jet streams are typically found about six miles above the earth’s surface and are powered by the huge temperature contrasts between the polar regions of the planet and the equator. The ribbons of strong winds influence global weather patterns and their positioning helps meteorologists to forecast the weather. Source:bbc.co.uk/weather, February 2012.
Climate change influencing the jet stream
There are many factors that influence the jet stream such as El Niño and La Nina. However, in this post, the changes in the global climate that affect the jet stream will be focused on.
The strength of the jet stream is directly proportional to the difference in temperature between the poles and the tropics. When it’s strong, the jet stream tends to take a straighter path, but when it’s weak it meanders. As the Arctic is experiencing warming at faster rates than the tropics, that difference is getting smaller, so the jet stream is weakening along with it.
“What that means for mid-latitudes, where Britain [and the U.S. are] located, is weather that stays in place for longer. Weather patterns will be more likely to get ‘stuck’ over a location, yielding long periods of rain and sun rather than Britain’s traditional ‘changeable’ skies.” (Source: wired.co.uk, February 14 by Duncan Geere)
Above, an image of the changing jet stream in the spring of 2012 in Britain. The unusual and lower-lying jet stream brings low pressure areas which is the cause of unsettled weather. Because the jet stream is lower than usual, it often gets stuck which brings the low pressure systems straight across England and Wales. And it is this stuck weather pattern that has resulted in breaking wet and stormy
weather records. (Source: BBC/weather, june 2012, By Chris Fawkes)
More frequent and extreme weather patterns in the future
It is becoming clear that extreme and unusual ‘once in a hundred years’ weather events will occur more regularly in the future. Indeed, there are many initiatives undertaken by nations all over the world to tackle global warming. The Kyoto and Montreal protocol, the Earth’s summit and many other international agreements and treaties are designed to reduce overall global emissions. However, as most of us already know, those initiatives are by far not enough to significantly reduce greenhouse gases to stop global temperatures rising. Therefore, the chances of stormier weather, persistent periods of rainfall or drought are more likely to occur more frequent, longer and more extreme in the future. However, that does not mean the battle against global warming is lost. There are still many things that can be done to reduce the impact of climate change in the future. Making smart choices about what we buy, how we use it, and how we dispose of it can make a big difference in the amount of waste we produce and the greenhouse gas emissions associated with our consumption.