Internal Setup Poll #6 : Climate

[RobWorham]

Misleading argument 5: ’Global warming computer models which predict the future climate are unreliable’

Computer models which predict the future climate are unreliable and based on a series of assumptions

What does the science say?

Modern climate models have become increasingly accurate in reproducing how the real climate 'works'. They are based on our understanding of basic scientific principles, observations of the climate and our understanding of how it functions.

By creating computer simulations of how different components of the climate system - clouds, the Sun, oceans, the living world, pollutants in the atmosphere and so on - behave and interact, scientists have been able to reproduce the overall course of the climate in the last century. Using this understanding of the climate system, scientists are then able to project what is likely to happen in the future, based on various assumptions about human activities.

It is important to note that computer models cannot exactly predict the future, since there are so many unknowns concerning what might happen. Scientists model a range of future possible climates using different scenarios of what the world will 'look like'. Each scenario makes different assumptions about important factors such as how the world's population may increase, what policies might be introduced to deal with climate change and how much carbon dioxide and other greenhouse gases humans will pump into the atmosphere. The resulting projection of the future climate for each scenario, gives various possibilities for the temperature but within a defined range.

While climate models are now able to reproduce past and present changes in the global climate rather well, they are not, as yet, sufficiently well-developed to project accurately all the detail of the impacts we might see at regional or local levels. They do, however, give us a reliable guide to the direction of future climate change. The reliability also continues to be improved through the use of new techniques and technologies.

[RobWorham]

Misleading argument 6: ’Global warming is all to do with the sun’

It's all to do with the Sun - for example, there is a strong link between increased temperatures on Earth with the number of sunspots on the Sun.

What does the science say?

Change in solar activity is one of the many factors that influence the climate but cannot, on its own, account for all the changes in global average temperature we have seen in the 20th Century.

Changes in the Sun's activity influence the Earth's climate through small but significant variations in its intensity. When it is in a more active' phase as indicated by a greater number of sunspots on its surface it emits more light and heat. While there is evidence of a link between solar activity and some of the warming in the early 20th Century, measurements from satellites show that there has been very little change in underlying solar activity in the last 30 years there is even evidence of a detectable decline and so this cannot account for the recent rises we have seen in global temperatures.

The magnitude and pattern of changes to temperatures can only be understood by taking all of the relevant factors both natural and human into account. For example, major volcanic eruptions produce a cooling effect because they blast ash and other particles into the atmosphere where they persist for a few years and reduce the amount of the Sun's energy that reaches the Earth's surface. Also, burning fossil fuels produces particles called sulphate aerosols which tend to cool the climate in the same way.

Over the first part of the 20th Century higher levels of solar activity combined with increases in human generated carbon dioxide to raise temperatures. Between 1940 and 1970 the carbon dioxide effect was probably offset by increasing amounts of sulphate aerosols in the atmosphere, and a slight downturn in solar activity, as well as enhanced volcanic activity.

During this period global temperatures dropped. However, in the latter part of the 20th Century temperatures rose well above the levels of the 1940s. Strong measures taken to reduce sulphate pollution in some regions of the world meant that industrial aerosols began to provide less compensation for an increasing warming caused by carbon dioxide. The rising temperature during this period has been partly abated by occasional volcanic eruptions.

[RobWorham]

Misleading argument 7: ’the climate is actually affected by cosmic rays’

The climate is actually affected by cosmic rays.

What does the science say?

Any effect that cosmic rays could have on the climate is not yet very well understood but, if there is one, it is likely to be small. Cosmic rays are fast moving particles which come from space, and release electric charge in the atmosphere.

Experiments done in a laboratory hint that cosmic rays could play a role in the development of tiny particles that could in turn play a part in the formation of clouds. If this happens in the same way in the atmosphere - which isn't proven - it might lead to more clouds, which generally have a cooling effect by reflecting the Sun's rays back into space. Whether the whole chain of processes actually occurs in the atmosphere is speculative, but some of the individual steps are plausible.

It has been proposed that this process would act to enhance the influences of the Sun on the climate. We know that when the Sun is more active its magnetic field is stronger and this deflects cosmic rays away from the Earth. So the argument is that a more active Sun would lead to fewer cosmic rays reaching the Earth, resulting in fewer clouds and therefore a warmer Earth.

However, observations of clouds and galactic cosmic rays show that, at most, the possible link between cosmic rays and clouds only produces a small effect. Even if cosmic rays were shown to have a more substantial impact, the level of solar activity has changed so little over the last few decades the process could not explain the recent rises in temperature that we have seen.

[RobWorham]

Misleading argument 8: ’the negative effects of climate change are overstated’

The scale of the negative effects of climate change is often overstated and there is no need for urgent action.

What does the science say?

Under one of its mid-range estimates(*), the Intergovernmental Panel on Climate Change (IPCC) - the world's leading authority on climate change - has projected a global average temperature increase this century of 2 to 3 ºC. This would mean that the Earth will experience a larger climate change than it has experienced for at least 10,000 years. The impact and pace of this change would be difficult for many people and ecosystems to adapt to.

In the short term, some parts of the world could initially benefit from climate change. For example, more northerly regions of the world may experience longer growing seasons for crops and crop yields may increase because increased levels of carbon dioxide in the atmosphere would have a fertilizing effect on plants.

However the IPCC has pointed out that as climate change progresses it is likely that negative effects would begin to dominate almost everywhere. Increasing temperatures are likely, for example, to increase the frequency and severity of weather events such as heat waves, storms and flooding.

Furthermore there are real concerns that, in the long term, rising levels of greenhouse gases in the atmosphere could set in motion large-scale and potentially abrupt changes in our planet's natural systems and some of these could be irreversible. Increasing temperatures could, for example, lead to the melting of large ice sheets with major consequences for low lying areas throughout the world.

And the impacts of climate change will fall disproportionately upon developing countries and the poor those who can least afford to adapt. Thus a changing climate will exacerbate inequalities in, for example, health and access to adequate food and clean water.

(*) See misleading argument 5 on computer model scenarios

[RobWorham]

VOTE TEMPERATE OR I'LL RELEASE MORE OF MY ROYAL SOCIETY QUOTES ON YOU!!!!!

[Zoid]

Wtf Rob??

[GeoModder]

Originally posted by RobWorham
VOTE TEMPERATE OR I'LL RELEASE MORE OF MY ROYAL SOCIETY QUOTES ON YOU!!!!!

Yes, Bwana

[RobWorham]

[GeoModder]

Ah Rob, too bad you weren't around with the SMAC demogames.

[RobWorham]

Indeed, I was rather slow in waking up to the value of the online community.

Having said that I did have fun playing with myself for all those years.........

[Zoid]

Do you have to wear gloves for those hairy palms of yours?

[RobWorham]

Ugh Ugh!!!

[GeoModder]

Originally posted by Zoid
Do you have to wear gloves for those hairy palms of yours?

Doesn't he work with food or something?

[Zoid]

Hence the gloves, duh!

[AdamTG02]

What have I unleashed?

Voted Temperate to avoid the Wrath of Isaac Newton, and also becase Rocky has no chance.