Internal Setup Poll #6 : Climate

[RobWorham]

THIS POLL CLOSES IN 2 DAYS FROM NOW!!!!

OK, the map script has finally been decided!!!

Now we have Terra, but what sort of climate do we want to play in??

The options are :

Temperate
Tropical
Arid
Rocky
Cold

Please remember that the map will be reviewed and tweaked by a human mapmaker before we get to play on it so all will be as fair and interesting as possible.......

THIS POLL CLOSES IN 2 DAYS FROM NOW!!!!

[Zoid]

Tropical Bring on the bananas!

[GeoModder]

Rocky Bring on those natural mountain barriers!

[FeMme]

Call me old fashioned but I like playing in a temperate climate.

[GeoModder]

20th century fashion is soooooo outdated.

[Zoid]

Talking about fashion, here's a recent pic of FeMme and her posse...

http://apolyton.net/forums/showthread.php?postid=4957382#post4957382

[GeoModder]

[RP21]

Tropical, I hate desert.

[AdamTG02]

I am withholding my vote in the perhaps vain hope that, in the next 24 hours, someone will make an actual argument.

[RobWorham]

I'm not vain, you are......

Good enough for you??

[AdamTG02]

I already know I'm vain. Next question?

[RobWorham]

Misleading argument 1: ’Climate change is nothing to do with humans’

The Earth's climate is always changing and this is nothing to do with humans. Even before the industrial revolution, when humans began pumping carbon dioxide into the atmosphere on a large scale, the earth experienced warm periods such as the medieval warm period.

What does the science say?

It is true that the world has experienced warmer or colder periods in the past without any interference from humans. The ice ages are well-known examples of global changes to the climate. There have also been regional changes such as periods known as the 'Medieval Warm Period', when grapes were grown extensively in England, and the 'Little Ice Age', when the River Thames sometimes froze over. However, in contrast to these climate phases, the increase of three-quarters of a degree centigrade (0.74°C) in average global temperatures that we have seen over the last century is larger than can be accounted for by natural factors alone.

The Earth's climate is complex and influenced by many things - particularly changes in the Earth's orbit in relation to the Sun, which has driven the cycles of ice ages in the past, as well as volcanic eruptions and variations in the energy being emitted from the Sun. But even when we take all these factors into account, we cannot explain the temperature rises that we have seen over the last 100 years both on land and in the oceans - for example, eleven of the last twelve years have been the hottest since records started in 1850.

So what is causing this increase in average global temperature? The natural greenhouse gas effect keeps the Earth around 30°C warmer than it would otherwise be and, without it, the Earth would be extremely cold. It works because greenhouse gases such as carbon dioxide, methane, but mostly water vapour, act like a blanket around the Earth. These gases allow the Sun's rays to reach the Earth's surface but hinder the heat they create from escaping back into space. Indeed, the ability of carbon dioxide and other greenhouse gases to trap heat in this way has been understood for nearly 200 years and is regarded as firmly established science.

Any increases in the levels of greenhouse gases in the atmosphere mean that more heat is trapped and global temperatures increase - an effect known as 'global warming'. We know from looking at gases found trapped in cores of polar ice that the levels of carbon dioxide in the atmosphere are now 35 per cent greater than they have been for at least the last 650,000 years. From the radioactivity and chemical composition of the gas we know that this is mainly due to the burning of fossil fuels, as well as the production of cement and the widespread burning of the world's forests. The increase in global temperature is consistent with what science tells us we should expect when the levels of carbon dioxide and other greenhouse gases in the atmosphere increase in the way that they have.

It has been alleged that the increased level of carbon dioxide in the atmosphere is due to emissions from volcanoes, but these account for less than one per cent of the emissions due to human activities.

[RobWorham]

Misleading argument 2: ’CO2 not responsible for global warming’

Carbon dioxide only makes up a small part of the atmosphere and so cannot be responsible for global warming.

What does the science say?

Carbon dioxide only makes up a small amount of the atmosphere, but even in tiny concentrations it has a large influence on our climate.

The properties of greenhouse gases such as carbon dioxide mean that they strongly absorb heat a fact that can be easily demonstrated in a simple laboratory experiment. While there are larger concentrations of other gases in the atmosphere, such as nitrogen, because they do not have these heat trapping qualities they have no effect on warming the climate whatsoever.

Water vapour is the most significant greenhouse gas. It occurs naturally, although global warming caused by human activities will indirectly affect how much is in the atmosphere through, for example, increased evaporation from oceans and rivers. This will, in turn, cause either cooling or warming depending on what form such as different types of clouds the water vapour occurs in.

Humans have been adding to the effect of water vapour and other naturally occurring greenhouse gases by pumping greenhouse gases such as carbon dioxide into the atmosphere through, for example, the burning of fossil fuels and deforestation. Before industrialization carbon dioxide made up about 0.03 per cent of the atmosphere or 280ppm (parts per million). Today, due to human influence it is about 380ppm. Even these tiny quantities have resulted in an increase in global temperatures of 0.75ºC (see misleading argument 1).

[RobWorham]

Misleading argument 3: ’rises in CO2 occur after global warming, not before’

Rises in the levels of carbon dioxide in the atmosphere are the result of increased temperatures, not the other way round.

What does the science say?

It is true that the fluctuations in temperatures that caused the ice ages were initiated by changes in the Earth's orbit around the Sun which, in turn, drove changes in levels of carbon dioxide in the atmosphere. This is backed up by data from ice cores which show that rises in temperature came first, and were then followed by rises in levels of carbon dioxide up to several hundred years later. The reasons for this, although not yet fully understood, are partly because the oceans emit carbon dioxide as they warm up and absorb it when they cool down and also because soil releases greenhouse gases as it warms up. These increased levels of
greenhouse gases in the atmosphere then further enhanced warming,
creating a positive feedback'.

In contrast to this natural process, we know that the recent steep increase in the level of carbon dioxide - some 30 per cent in the last 100 years - is not the result of natural factors. This is because, by chemical analysis, we can tell that the majority of this carbon dioxide has come from the burning of fossil fuels. And, as set out in 'misleading argument 1 ', carbon dioxide from human sources is almost certainly responsible for most of the warming over the last 50 years. There is much evidence that backs up this explanation and none that conflicts with it.

Warming caused by greenhouse gases from human sources could lead to the release of more greenhouse gases into the atmosphere by stimulating natural processes and creating a "positive feedback", as described above.

[RobWorham]

Misleading argument 4: ’Temperature observations don’t support the theory’

Observations of temperatures taken by weather balloons and satellites do not support the theory of global warming.

What does the science say?

It is true that in the early 1990s initial estimates of temperatures in the lowest part of the earth's atmosphere, based on measurements taken by satellites and weather balloons, did not mirror the temperature rises seen at the earth's surface. However these discrepancies have been found to be related to problems with how the data was gathered and analysed and have now largely been resolved.

Our understanding of global warming leads us to expect that both the lower atmosphere the troposphere where most greenhouse gases are found and the surface of the earth should warm as a result of increased levels of greenhouse gases in the atmosphere. At the same time, the lower stratosphere the part of the atmosphere above the greenhouse gas blanket' should cool.

Some have argued that climate change, as a result of human activities, isn't happening because early measurements taken from satellites and weather balloons seemed to show that virtually no warming was happening in the troposphere. However, this has been found to be due to errors in the data. Satellites were found, for example, to be slowing and dropping in orbit slightly, leading to inconsistencies in their measurements. Variations between the instruments onboard different satellites also led to discrepancies a problem that has also been found with weather balloons. Furthermore, a mathematical error in one of the original analyses of satellite data meant that it showed less warming in the troposphere. However, once adjustments are made to take account of these and other issues, the warming in the troposphere is shown to be broadly consistent with the temperature trends we see at the earth's surface.

In addition, the lower stratosphere has been shown to be cooling and this corresponds with our understanding of what effect global warming should have on this part of the atmosphere. However, some of this cooling is not related to increased levels of greenhouse gases but due to a different impact that humans have had on the atmosphere the depletion of the ozone layer. Ozone warms the stratosphere by trapping incoming energy from the sun. This reduction of ozone also has knock on' effects on other parts of the atmosphere, underlining the importance of taking all factors into account when looking at what is happening to our climate.

It is fair to note that in tropical regions of the world there are still some discrepancies between what computer models lead us to expect regarding temperatures at the surface and in the troposphere and what we actually see. However, these disagreements are within the bounds of the likely remaining errors in the observations and uncertainties in the models.