farestveitandmjanger

Problem to be addressed: Global warming: naturally or made by the human being? Elise Askeland Farestveit & Emil Mjanger

Changes in climate, human made or natural? Global warming is, to cut a long story short, warmer temperatures and increased greenhouse effect. It affects the whole world – that is the reason why we call it global warming. Some researchers think that radiation from the sun is a more important reason for global warming than the human beings spill of CO2. This is a big discussion, but one thing is for sure: we have to do what we are able to do to stop the global warming. It will affect us, more than we are possible to imagine, in the future. But, is the global warming made by the human being or is it naturally changes in the climate, like it have been before when the temperatures have changed? This is what we will discuss in this task – we will give you arguments for both statements.

Naturally causes The climate on our planet has always been changing. Different periods earlier have had different average temperatures. This is one of the reasons why some researchers believe that this is just one of the naturally made periods with a warmer temperature than we are used to. The last 2 million years the climate has been switching among ice ages, interglacial stages, and warmer cycles. This has been affected by cyclic variations in the Earth's orbit around the sun, the axis of the Earth’s angle of inclination and by natural causes. Still, the six warmest years in this century have already found place in the 80’s or 90’s. This is called global warming, and most of the researchers agree with that. The question they ask is if the changes are natural or a phenomenon made by the human being.

The human made spill of CO2 is 3% of the total CO2 spill at earth. CO2 affect the greenhouse gasses, and therefore the global warming. Is the spill of CO2 stable? Naturally spill of CO2 can fluctuate because of eruption, variation by the sun etc., and create natural changes in the climate. This also includes methane and laughing gas.

Glaciers If we take a look at the glaciers, researchers can tell us that deep, old layers can tell that there have been a change between warm and cold periods, where glaciers have shrank and increased. Therefore, we can say that this period we are in at the moment is one of the warmer periods, which is natural, and have existed earlier as well as today. The cap of the ice is very varietal. Five millions years ago the glaciers at Antarctica was gone. This is an argument for the natural changes in the climate. It is totally normal that the climate and the temperatures fluctuate. So are the climate changes we experience today naturally?

Arctic

Let’s take a look at how the climate changes affect the Arctic region. This is essential, since the ice at Arctic is important for water level all over the world. The Arctic region is the recipient of pollution that comes from the northern hemisphere. When human beings pollute, this affects the environment. CO2 is the most discussed gas that affects the climate. When the temperature increase, affected by CO2, this will affect the sea level since the ice melts faster when the temperature increase. This has many consequences, and many of them are gravely. The marine food chain experiences this often, since it is very effective when it comes to gather and store fat-soluble environmental poisons. The greatest change as a result of the global climate changes is the melt-down of the glaciers. This leads to rise of the sea level. In the upcoming hundred years it is expected that the greatest contribution to raised sea level will come from smaller glaciers and ice caps, not from the great continental ice sheets in Arctic.

The polar bear is an important animal, especially in the Arctic region. The polar bear get influenced by the climate changes, which is serious since the polar bear is at the top of the food chain. Environmental poison affects its sex hormone, metabolism hormone and the polar bears immune defence. This can lead to troubles during reproduction of polar bears, and the new bears might be born at the wrong time of the year. This can lead to troubles during adjustment, and since the temperatures is changing dramatically, this might be too much for the polar bear. In the periods with little food available, the polar bear might struggle to survive. The polar bears might also, actually, get brittle bones and impaired ability to learn, co-ordinate and remember. This can reduce the polar bears successful hunting and its ability to navigate in the icy area.

Some researchers believe that cosmic radiation is one of the main reasons for global warming. These investigators don’t blame the humans for the global warming, but the elemental forces are the point of departure. The warmest year since the 14 hundred century was in 1997, but we assume that it was warmer in the 11 hundred century (about 0,75 degrees warmer than today), and for about 2000 - 3000 years ago there was about 3 degrees warmer than today.

The climate gets affected by several elements. Among other factors radiation from the sun, the quantity of greenhouse gasses and cloud ceiling above the Earth’s surface matters in the global warming process. The greenhouse gas is the most important, and CO2 is the most effective. The less CO2 in the atmosphere, the lower is the temperature. Increase of CO2 gives increased temperature. Industrialising in modern times gets most the blame for the global warming. But the greatest warming occurred before 1940, when the massive production that spills most of the CO2 from the human beings into the atmosphere established. If CO2 were a major greenhouse gas, we would expect that the temperature would increase, but in the time period 1940 – 1975 the temperature felt, even though the amount of CO2 increased. Therefore we can wonder if the CO2 don’t have that great influence on the climate as many thinks it has. CO2 is besides a natural gas.

Polar bears The very much discussed polar bear is like every other living creature shaped by the environment it lives in. this has resulted in a split in genetics between them and their cuisines, the grizzly bear and the black bear. For example is the white colour the polar bear has, is a disguise that helps him in his hunting. Another example is the fat present in the mother’s milk, the brown bear and the black bear has a fat present of 23% but the polar bear has 33% fat in the breast milk. This is an example of how the evolution has helped the different species to survive the different living conditions.

Volcanoes

Volcanoes are one of the main reasons for CO2-spill. When there is an eruption this will result in a lot of CO2-spill. Volcanoes dump more CO2 yearly than humans. In addition to the volcanoes plants, animals, bacteria, compost and the ocean spill CO2.

Consequences for the environment - heat waves and periods of unusually warm weather - ocean warming - sea-level rise and coastal flooding - glaciers melting - Arctic and Antarctic warming - Spreading disease, particularly in wildlife - earlier spring arrival - plant and animal range shifts and population changes - coral reef bleaching - downpours, heavy snowfalls, and flooding - droughts and fires

Conclusion Either way, if the climate changes are natural or made by the human being - we can’t work against mother nature, we have to adjust to her.

SOURCES: Naturlige klimaendringer? Hans Martin Seip, 18.10.2006 http://www.cicero.uio.no/sporsmal/detail.aspx?faqid=61 [Lest: 16.02.09, 11.15]

Finner spor etter store naturlige klimaendringer, 17.03.2008 14:16 http://web3.aftenbladet.no/utenriks/article420376.ece [Lest: 17.02.09, 08.32]

Utdanningsdirektoratet, Naturfagsenteret, GLOBE Norge og Europa http://www.nilu.no/pomi/leverfil.cfm?id=22617&type=6 [Lest: 17.02.09, 09.09]

Kan isbjørnene overleve klimaendringene? Kristen Ulstein, 10.09.2008 http://www.ipy.no/prosjekter/BearHealth [Lest: 17.02.09, 10.20]

Global Warming: Early warning signs, 1999 http://www.climatehotmap.org/ [Lest: 19.02.09, 12.36]

Global oppvarming, mars 2008. http://iflirt.no/innlegg/2170__global_oppvarming_ [Lest: 23.02.09 – 17.50] Global oppvarming og svalbard, (09.03.07 09:36) http://vgd.no/samfunn/alle-snakker-om-vaeret/tema/1187040/tittel/global-oppvarming-og-svalbard [Lest: 24.02.09 – 09.20]

klimaendring, menneskeskapt (fredag, mars 16th 2007) http://22495.vgb.no/ [Lest: 25.02.09 – 11.20]

HER EMIL LIMER DU INN DET DU SKAL SKRIVE: UNDER HER. UNDER. IKKJE OVER. Changes in climate, human made or natural?

Human made?

Most scientists today agree that the changes in environment are, not only human made, but dramatically increased by human interests. Scientists believe that the level of CO2 today is 20% above what it has been the past 650 000 years.

The UN’s 4. main report represent a few main points:

•	There is changes in the climate •	The main part of the observed growing temperature since the middle of the 20th century is mostly from greenhouse gases •	Higher temperature and an increasing of the sea level will continue independent of how much people reduce their discharge. •	The possibility that this is caused only by natural changes in climate is less then 5% •	The temperature world-wide will expand with around 3-4degres, the sea level will rise approximately 18-59cm

(kya=1000 years ago, ppm=CO2 parts per million (volume))

The blue line illustrates the CO2 level found the last 400 000 years by ice cores drilled at the Vostok station in Antarctica.

(Blue line=changes in CO2 level, red line=temperature) What causes the global warming? Many people hear talk about eradicated animals and maybe most the polar bear. The fact is that the polar bear is not an eradicated animal, it even hunting on it some places. But there are other animals that are way more affected by the global warming. There are to frog species in the rainforest that already are extricated. Big coral-reefs die because of the higher temperature. Okay, coral-reefs are something only rich scuba-divers admire. No, a coral-reef is an oasis in the ocean, a big reef houses thousands of thousands of different fish and species.

An other fact is the glaciers; they decrease faster then ever before witch results in more water witch results in higher temperature sins ice reflect the hot radiations from the sun way more than water does.

So, where does all this CO2 come from?

- us. Kilder: http://no.wikipedia.org/wiki/Global_oppvarming http://no.wikipedia.org/wiki/FNs_klimapanel