climate change for dummies
Never really understood what all the fuzz is about? Read this! [Under construction].
There have always been natural fluctuations in climate. Why is the current global warming any different?
What is the greenhouse effect?
What are greenhouse gases?
What is happening to the Greenland ice cap?
Does planting trees really help balancing the effects of global warming?
What's true (and not) about An Inconvenient Truth?
What's true (and not) about The Great Global Warming Swindle?
I just don't buy that crap about global warming being caused by humans. So why should I care?
What can I do to stop climate change (mitigation)?
What can I do to adapt to climate change (adaptation)?
This spring scientists analysed trace gases trapped in Antarctic ice cores to reconstruct greenhouse gas concentrations up to 800,000 years ago. The concentrations show that during that entire period of time, there have never been higher concentrations of carbon dioxided and methane gas as the current levels.1 So although there have been natural fluctuations in the past, they have never reached the high levels we see today, and there remains a strong correlation of methane and carbon dioxide with temperature.
What is the greenhouse effect?
It is a good thing there is such a thing as the greenhouse effect, otherwise life on Earth would not have been possible. The greenhouse effect is essentially a natural process.
Sunlight alone does not sufficiently warm the Earth. Sunlight warms the earth, ocean's and clouds, who emit infra-red radiation. Water vapour, carbon dioxide and some other naturally occurring gases can absorb part of this radiation, comfortably warming the atmosphere to an average of 15°C. Without greenhouse gases average global surface temperature would be -18°C.
The greenhouse effect thanks it's impopularity to increased human emission of greenhouse gases into the atmosphere, causing an increased trapping of infra-red radiation and global warming.
Greenhouse gases are useful gases that keep the Earth's surphase warm, so that life can be sustained. However, too much gases cause global warming and has a negative impact on life. About three-quarters of the natural greenhouse effect is due to water vapour. The next most significant greenhouse gas is carbon dioxide. Methane, nitrous oxide, ozone in the lower atmosphere, and CFCs are also greenhouse gases.
What is happening to the Greenland ice cap?
It is melting! That's for sure. Scientsits are at this moment actually investigating the melting of the Greenland ice cap. They know the Greenland ice cap is more exposed to global warming than the larger Antarctic ice sheet and is melting fast.2 It is not yet known how much it contributes to rising sea levels as part of the melting cap will drain into the cold snow and simply refreeze.
Does planting trees really help balancing the effects of global warming?
According to the UN, it does! As trees grow they absorb and store carbon dioxide, thus reducing global warming. Carbon is stored in the forest biomass, in the trunks, branches, foliage and roots of trees and in the soil.3 In a well managed forest, carbon storage never stops as new trees replace those that have been harvested. Even after harvest, wood products continue to store the carbon. At the moment (2008) Europe's forests are covering 44 percent of Europe's land area and continue to expand at a rate of about 360 million cubic metres annualy.
What's true (and not) about An Inconvenient Truth?
An Inconvenient Truth is a documentory film made by Al Gore, focusing on global warming and climate change as a result of human actions. Scientists have affirmed that hurricanes have doubled over the last couple of years, deaths from global warming will increase, and more species will be driven to extiction. Some things however remain controversial. It is not true that..:
1. .. global warming causes Mount Kilimanjaro's snow to melt.
The snows of Kilimanjaro are retreating, but according to studies in several scientific journals, the retreat began in the late 19th century — before most human greenhouse gases were emitted. It is largely due to the decline in precipitation (snowfall) on the mountain as a result of the clearing and burning of the rainforests at its base for agriculture. Humans are to blame for the retreat of Kilimanjaro's glaciers, global warming is not.5
2. .. melting polar ice sheets will cause mass flooding.
In An Inconvenient Truth it is stated that melting polar ice will cause sea levels to rise by as much as 40 feet. However, as ice is decreasing around the edges of Greenland and Antarctica, ice and snow is accumulating in the interior. A 2005 study by a NASA scientist concludes that there is a net loss of ice that will result in higher sea levels. But the loss is occurring slowly: 0.05 millimeters on average per year.5
What's true (and not) about The Great Global Warming Swindle?
The Great Global Warming Swindle (2007) is a documentary film featuring scientists, economics and politicians who are skeptical about the human contribution to global warming and the role of the International Platform Communication on Climate Change (IPCC). The film was in turn received withskeptisism and critique. John Houghton from the IPCC acknowledges that ice core samples show CO2 driven by temperature - which might serve as evidence for temperature increase as a cause of increased CO2-leves, rather than the other way around. Some things mentioned in the documentary are not true. It is not true that..:
1. .. there is no correlation between CO2-concentrations and temperature oscillations now or in the past.
There is a very clear correlation, although it has never been said this gives proof of global warming due to increased CO2.6
2. ..changes in sun activity explain global warming much more accurately.
According to the Physikalisch-Meteorologisches Observatorium Davos sun activity has not significantly increased since 1979. It is therefore unlikely to have caused recent global warming.6
3. ..observed extreme weather events are not caused by humans.6
Scientists of the British Meteorological Institute concluded that the a higher concentration of greenhouse gases and other air pollutants have probably doubled the chance at extreme weather in Europe. 6
I just don't buy that crap about global warming being caused by humans. So why should I care?
If you are not convinced by the evidence indicating that humans are causing global warming and climate change, you probably think reducing the burning of fossil fuels is rather useless. Caused by humans or just a natural effect: global warming is taking place, average temperatures are rising, polar ice caps show netto melt-off and temperatures and weather get more extreme. Even if not everyone agrees humans are the cause of global warming, humans can (and should) act to adapt themselves to climate change. Build bigger dikes, invent new methods of irrigation, think of solutions for drought, etc. Adaptation is neccessary to make the world climate proof.
What can I do to stop climate change (mitigation)?
1. Change your lightbulbs for energy saving bulbs.7
2. Recycle left-over vegetables, paper and glass bottles and - if that's possible in your area - plastic and take old, broken electrical appliances to the scrap-heap.7
3. Be sparing with electrical heating and insulate your house (think about draft through windows and doors.7
4. Turn off machines your not using, do not let them run on standby, like your computer sceen.
5. Commute to work if possible or try working at home for one day a week.7
6. When choosing your holiday destination, think about transportation on the spot and how you are getting there. Trains and buses are more environmental friendly than airplanes.
What can I do to adapt to climate change (adaptation)?
Politicians, local, national and global, have to take steps to make sure their nations and cities are climate proofed within decades. Dikes need to be build, cities have to be adapted to counter heat stress and farmers need to devise new ways to divide crops during dryer and or wetter seasons. However, there are some things you can do yourself.
1. Depending on where you're living, those living in urban areas will want to insulate their houses to keep the heat out during hot seasons.
2. Look after yourself during extreme hot weather: more and more people die of heat stress during extreme hot summers (in London a couple of years ago more people died of heat stress during a couple of weeks than in traffic during a whole year). Listen to the forcast, stay cool and drink lots of water. 8
3. Donate money for projects in developing countries dealing with adaptation to global warming. Developing countries will be struck hardest of all: climate change and global warming will have the biggest impact in the already hot and dry countries situated around the equator. Rising sea levels will directly affect millions of poor communities living on beaches, by the sea and at rivers.