Climate Change – the real truth?

Of course no matter what people say we do not know the truth but we may know some of the truths.

What is more troubling about the climate change debate is that, as usual, it is being hijacked. On one side climate change activists may leave out some important facts, because we are not all scientists and we would not understand ( I heard this argument put forward as a reason for children being excluded from the climate change debate -they are too young to understand).

On the other side -the climate change denyers/disbelievers -they often have vested interests and damn all evidence as being trumped up by governments who want to tax people more.

What has been forgotten is the sum total of our destructiveness – we have forgotten about the plundering of the tropical rain forests, overfishing of the oceans, urban pollution, destruction of habitat and species and the list gets longer each day. It is the sum total of our effects on our environment that we should be concerned about -  not just climate change. The evidence about climate change has to be seen in the context of recent human activities (which we know a lot about) and the broader climatic cycles that can only be interpreted through archaeological and geological studies (such as inter-glacial periods etc) which we are still learning about.

What do we know about?

Habitat destruction

Habitat destruction

The expansion of agricultural activity has led to the destruction of huge areas of natural habitats, including forests, grasslands and wetlands, in nearly all regions of the world. For tropical forests, the richest habitat for biodiversity, logging is typically the first major pressure, often providing access to remote areas and leading to further clearance and degradation. The expansion and development of urban areas and infrastructure also reduces natural habitats, and new roads give access to additional areas, which results in further losses. The relative importance of these factors varies in different parts of the world (box 2), but all play a significant part in the destruction of habitats and therefore in driving ecosystem change.

habitat destruction

Pollution

The urban areas of Europe, North and South America as well as Asia are some the world’s major producers of nitrogen dioxide (NO2) pollution. Other significant polluters are the coal-fired power stations of South Africa and bio-mass burning in other parts of the African continent. Heavily used shipping lanes such as the Red Sea also contribute significantly to the earth’s man-made pollution.

These are some of the findings of 18 months of observations by the European Space Agency (ESA) satellite Envisat. The images produced by Envisat make clear the impact of human activities on air quality and the spread of urban pollution.

no2levels_europe

Overfishing

zambezi_overfishing

Is overfishing a problem?

The FAO scientists publish a two yearly report (SOFIA) on the state of the world’s fisheries and aquaculture. 2 The report is generally rather conservative regarding the acknowledging of problems but does show the main issues. In general it can be stated that the SOFIA report is a number of years behind time of the real situation.

  • 52% of fish stocks are fully exploited
  • 20% are moderately exploited
  • 17% are overexploited
  • 7% are depleted
  • 1% is recovering from depletion

The above shows that over 25% of all the world’s fish stocks are either overexploited or depleted. Another 52% is fully exploited, these are in imminent danger of overexploitation (maximum sustainable production level) and collapse. Thus a total of almost 80% of the world’s fisheries are fully- to over-exploited, depleted, or in a state of collapse. Worldwide about 90% of the stocks of large predatory fish stocks are already gone. In the real world all this comes down to two serious problems.

  • We are losing species as well as entire ecosystems. As a result the overall ecological unity of our oceans are under stress and at risk of collapse.
  • We are in risk of losing a valuable food source many depend upon for social, economical or dietary reasons.

Examples of the outcomes from overfishing exist in areas such as the North Sea of Europe, the Grand Banks of North America and the East China Sea of Asia.[2] In these locations, overfishing has not only proved disastrous to fish stocks but also to the fishing communities relying on the harvest. Like other extractive industries such as forestry and hunting, fishery is susceptible to economic interaction between ownership or stewardship and sustainability, otherwise known as the tragedy of the commons.

And now the arguments about climate change (ref:BBC)

So what are their arguments, and how are they countered by scientists who assert that greenhouse gases, produced by human activity, are the cause of modern-day climate change?

1. EVIDENCE THAT THE EARTH’S TEMPERATURE IS GETTING WARMER IS UNCLEAR
Sceptic Counter
Instruments show there has been some warming of the Earth’s surface since 1979, but the actual value is subject to large errors. Most long-term data comes from surface weather stations. Many of these are in urban centres which have been expanding and using more energy. When these stations observe a temperature rise, they are simply measuring the “urban heat island effect”. In addition, coverage is patchy, with some regions of the world almost devoid of instruments. Data going back further than a century or two is derived from “proxy” indicators such as tree-rings and stalactites which, again, are subject to large errors. Warming is unequivocal. Ocean measurements, decreases in snow cover, reductions in Arctic sea ice, longer growing seasons, balloon measurements, boreholes and satellites all show results consistent with records from surface weather stations. The urban heat island effect is real but small; and it has been studied and corrected for. Analyses by Nasa, for example, use only rural stations to calculate trends. Research has shown that if you analyse long-term global temperature rise for windy days and calm days separately, there is no difference. If the urban heat island effect were large, you would expect to see more warming on calm days when more of the heat stays in the city. Furthermore, the pattern of warming globally doesn’t resemble the pattern of urbanisation, with the greatest warming seen in the Arctic and northern high latitudes. Globally, there is a warming trend of about 0.8C since 1900, more than half of which has occurred since 1979.
2. IF THE AVERAGE TEMPERATURE WAS RISING, IT HAS NOW STOPPED
Sceptic Counter
Since 1998 – more than a decade – the record, as determined by observations from satellites and balloon radiosondes, shows no discernible warming. The year 1998 was exceptionally warm because of a strong El Nino event, while 2008 was unusually cold because of La Nina conditions. Variability from year to year is expected, and picking a specific warm year to start an analysis (or a cold one to end with) is “cherry-picking”. If you start in 1997 or 1999 you will see a sharp rise. Furthermore, while the UK Met Office regards 1998 as the hottest year yet, Nasa thinks it was 2005 (they use the same data but interpret it differently). According to the Met Office, the 10 warmest years in the modern record have all occurred since 1997.
3. THE EARTH HAS BEEN WARMER IN THE RECENT PAST
Sceptic Counter
The beginning of the last Millennium saw a “Medieval Warm Period” when temperatures, certainly in Europe, were higher than they are now. Grapes grew in northern England. Ice-bound mountain passes opened in the Alps. The Arctic was warmer in the 1930s than it is today. There have been many periods in Earth history that were warmer than today – for example, the last interglacial (125,000 years ago) or the Pliocene (three million years ago). Those variations were caused by solar forcing, the Earth’s orbital wobbles or continental configurations; but none of those factors is significant today compared with greenhouse warming. Evidence for a Medieval Warm Period outside Europe is patchy at best, and is often not contemporary with the warmth in Europe. As the US National Oceanographic and Atmospheric Administration (Noaa) puts it: “The idea of a global or hemispheric Medieval Warm Period that was warmer than today has turned out to be incorrect.” Additionally, although the Arctic was warmer in the 1930s than in the following few decades, it is now warmer still. One recent analysis showed it is warmer now than at any time in the last 2,000 years.
4. COMPUTER MODELS ARE NOT RELIABLE
Sceptic Counter
Computer models are the main way of projecting future climate change. But despite decades of development they are unable to model all the processes involved; for example, the influence of clouds, the distribution of water vapour, the impact of warm seawater on ice-shelves and the response of plants to changes in water supply. Climate models follow the old maxim of “you put garbage in, you get garbage out”. Models will never be perfect and they will never be able to forecast the future exactly. However, they are tested and validated against all sorts of data. Over the last 20 years they have become able to simulate more physical, chemical and biological processes, and work on smaller spatial scales. The 2007 IPCC report produced regional climate projections in detail that would have been impossible in its 2001 assessment. All of the robust results from modelling are backed up by theoretical science or observations.
5. THE ATMOSPHERE IS NOT BEHAVING AS MODELS WOULD PREDICT
Sceptic Counter
Computer models predict that the lower levels of the atmosphere, the troposphere, should be warming faster than the Earth’s surface. Measurements show the opposite. So either the models are failing, or one set of measurements is flawed, or there are holes in our understanding of the science. Interpretation of the satellite data has not always been straightforward – but it does not show the opposite of what computer models predict. Two separate analyses show consistent warming, one faster than the surface and one slightly less fast. Information from balloons has its own problems but the IPCC concluded in 2007: “For the period since 1958, overall global and tropical tropospheric warming estimated from radiosondes has slightly exceeded surface warming”.
6. CLIMATE IS MAINLY INFLUENCED BY THE SUN
Sceptic Counter
Earth history shows climate has regularly responded to cyclical changes in the Sun’s energy output. Any warming we see can be attributed mainly to variations in the Sun’s magnetic field and solar wind. Solar variations do affect climate, but they are not the only factor. As there has been no positive trend in any solar index since the 1960s (and a negative trend more recently), solar forcing cannot be responsible for the recent temperature trends. The difference between the solar minimum and solar maximum over the 11-year solar cycle is 10 times smaller than the effect of greenhouse gases over the same interval.
7. A CARBON DIOXIDE RISE HAS ALWAYS COME AFTER A TEMPERATURE INCREASE NOT BEFORE
Sceptic Counter
Ice-cores dating back nearly one million years show a pattern of temperature and CO2 rise at roughly 100,000-year intervals. But the CO2 rise has always come after the temperature rise, not before, presumably as warmer temperatures have liberated the gas from oceans. This is largely true, but largely irrelevant. Ancient ice-cores do show CO2 rising after temperature by a few hundred years – a timescale associated with the ocean response to atmospheric changes mainly driven by wobbles in the Earth’s orbit. However, this time, CO2 is leading temperature. Furthermore, the situation today is dramatically different. The extra CO2 in the atmosphere (35% increase over pre-industrial levels) is from man-made emissions, and levels are higher than have been seen in 650,000 years of ice-core records. They may in fact be higher than at any time in the last three million years.
8. LONG-TERM DATA ON HURRICANES AND ARCTIC ICE IS TOO POOR TO ASSESS TRENDS
Sceptic Counter
Before the era of satellite observation began in the 1970s, measurements were ad-hoc and haphazard. Hurricanes would be reported only if they hit land or shipping. The extent of Arctic ice was measured only during expeditions. The satellite record for these phenomena is too short to justify claims that hurricanes are becoming stronger or more frequent, or that there is anything exceptional about the apparent shrinkage in Arctic ice up to 2007. The Arctic Climate Impact Assessment project notes that systematic collection of data in parts of the Arctic began in the late 18th Century. The US National Hurricane Center notes that “organised reconnaissance” for Atlantic storms began in 1944. So although historical data is not as complete as one might like, conclusions can still be drawn from it. And the IPCC does not claim that global warming will make hurricanes more frequent – its 2007 report says that if anything, they are likely to become less frequent, but more intense.
9. WATER VAPOUR IS THE MAJOR GREENHOUSE GAS; CO2 IS RELATIVELY UNIMPORTANT
Sceptic Counter
The natural greenhouse effect keeps the Earth’s surface about 33C warmer than it would otherwise be. Water vapour is the most important greenhouse gas, accounting for about 98% of all warming. So changes in carbon dioxide or methane concentrations would have a relatively small impact. Water vapour concentrations are rising, but this does not necessarily increase warming – it depends how the water vapour is distributed. The statement that water vapour is “98% of the greenhouse effect” is simply false. In fact, it does about 50% of the work; clouds add another 25%, with CO2 and the other greenhouse gases contributing the remaining quarter. Water vapour concentrations are increasing in response to rising temperatures, and there is evidence that this is adding to warming, for example in Europe. The fact that water vapour is a feedback is included in all climate models.
10. PROBLEMS SUCH AS HIV/AIDS AND POVERTY ARE MORE PRESSING THAN CLIMATE CHANGE
Sceptic Counter
The Kyoto Protocol has not reduced emissions of greenhouse gases noticeably. The targets were too low, applied only to certain countries, and have been rendered meaningless by loopholes. Many governments that enthuse about the treaty and want a successor are not going to meet the reduction targets that they signed up to in Kyoto. Even if it is real, man-made climate change is just one problem among many facing the world’s rich and poor alike. Governments and societies should respond proportionately, not pretend that climate is a special case. Poorer countries should not be forced to constrain their emissions and therefore their economic growth, as they will be under a Copenhagen treaty. Some economists believe that a warmer climate would, on balance, improve lives. Arguments over the Kyoto Protocol are outside the realms of science, although it certainly has not reduced greenhouse gas emissions as far or as fast as the IPCC indicates is necessary. The latest IPCC Working Group 2 report suggest that the impact of man-made climate change will on balance be deleterious, particular to the poorer countries of the tropics, although colder regions may see benefits such as increased crop yields. Investment in energy efficiency, new energy technologies and renewables are likely to benefit the developing world. A Copenhagen treaty would not force emission constraints on the world’s poorest countries – in fact, it will funnel money to them for technology and climate protection, helping clean growth. More affluent developing countries – including China – will have to constrain their emissions growth but they agreed to this at the 2007 Bali summit.
In case the two columns are not completely visible,I will try and separate them for ease of use:

1. EVIDENCE THAT THE EARTH’S TEMPERATURE IS GETTING WARMER IS UNCLEAR

Sceptic

Instruments show there has been some warming of the Earth’s surface since 1979, but the actual value is subject to large errors. Most long-term data comes from surface weather stations. Many of these are in urban centres which have been expanding and using more energy. When these stations observe a temperature rise, they are simply measuring the “urban heat island effect”. In addition, coverage is patchy, with some regions of the world almost devoid of instruments. Data going back further than a century or two is derived from “proxy” indicators such as tree-rings and stalactites which, again, are subject to large errors.

Counter

Warming is unequivocal. Ocean measurements, decreases in snow cover, reductions in Arctic sea ice, longer growing seasons, balloon measurements, boreholes and satellites all show results consistent with records from surface weather stations. The urban heat island effect is real but small; and it has been studied and corrected for. Analyses by Nasa, for example, use only rural stations to calculate trends. Research has shown that if you analyse long-term global temperature rise for windy days and calm days separately, there is no difference. If the urban heat island effect were large, you would expect to see more warming on calm days when more of the heat stays in the city. Furthermore, the pattern of warming globally doesn’t resemble the pattern of urbanisation, with the greatest warming seen in the Arctic and northern high latitudes. Globally, there is a warming trend of about 0.8C since 1900, more than half of which has occurred since 1979.

2. IF THE AVERAGE TEMPERATURE WAS RISING, IT HAS NOW STOPPED

Sceptic

Since 1998 – more than a decade – the record, as determined by observations from satellites and balloon radiosondes, shows no discernible warming.

The year 1998 was exceptionally warm because of a strong El Nino event, while 2008 was unusually cold because of La Nina conditions. Variability from year to year is expected, and picking a specific warm year to start an analysis (or a cold one to end with) is “cherry-picking”. If you start in 1997 or 1999 you will see a sharp rise. Furthermore, while the UK Met Office regards 1998 as the hottest year yet, Nasa thinks it was 2005 (they use the same data but interpret it differently). According to the Met Office, the 10 warmest years in the modern record have all occurred since 19

3. THE EARTH HAS BEEN WARMER IN THE RECENT PAST

Sceptic

The beginning of the last Millennium saw a “Medieval Warm Period” when temperatures, certainly in Europe, were higher than they are now. Grapes grew in northern England. Ice-bound mountain passes opened in the Alps. The Arctic was warmer in the 1930s than it is today

Counter

There have been many periods in Earth history that were warmer than today – for example, the last interglacial (125,000 years ago) or the Pliocene (three million years ago). Those variations were caused by solar forcing, the Earth’s orbital wobbles or continental configurations; but none of those factors is significant today compared with greenhouse warming. Evidence for a Medieval Warm Period outside Europe is patchy at best, and is often not contemporary with the warmth in Europe. As the US National Oceanographic and Atmospheric Administration (Noaa) puts it: “The idea of a global or hemispheric Medieval Warm Period that was warmer than today has turned out to be incorrect.” Additionally, although the Arctic was warmer in the 1930s than in the following few decades, it is now warmer still. One recent analysis showed it is warmer now than at any time in the last 2,000 years.

4.computer models

Computer models are the main way of projecting future climate change. But despite decades of development they are unable to model all the processes involved; for example, the influence of clouds, the distribution of water vapour, the impact of warm seawater on ice-shelves and the response of plants to changes in water supply. Climate models follow the old maxim of “you put garbage in, you get garbage out”.

counter

Models will never be perfect and they will never be able to forecast the future exactly. However, they are tested and validated against all sorts of data. Over the last 20 years they have become able to simulate more physical, chemical and biological processes, and work on smaller spatial scales. The 2007 IPCC report produced regional climate projections in detail that would have been impossible in its 2001 assessment. All of the robust results from modelling are backed up by theoretical science or observations.

5. THE ATMOSPHERE IS NOT BEHAVING AS MODELS WOULD PREDICT

Sceptic

Computer models predict that the lower levels of the atmosphere, the troposphere, should be warming faster than the Earth’s surface. Measurements show the opposite. So either the models are failing, or one set of measurements is flawed, or there are holes in our understanding of the science.

Counter

Interpretation of the satellite data has not always been straightforward – but it does not show the opposite of what computer models predict. Two separate analyses show consistent warming, one faster than the surface and one slightly less fast. Information from balloons has its own problems but the IPCC concluded in 2007: “For the period since 1958, overall global and tropical tropospheric warming estimated from radiosondes has slightly exceeded surface warming”.

6. CLIMATE IS MAINLY INFLUENCED BY THE SUN

Sceptic

Earth history shows climate has regularly responded to cyclical changes in the Sun’s energy output. Any warming we see can be attributed mainly to variations in the Sun’s magnetic field and solar wind.

Counter

Solar variations do affect climate, but they are not the only factor. As there has been no positive trend in any solar index since the 1960s (and a negative trend more recently), solar forcing cannot be responsible for the recent temperature trends. The difference between the solar minimum and solar maximum over the 11-year solar cycle is 10 times smaller than the effect of greenhouse gases over the same interval.

7. A CARBON DIOXIDE RISE HAS ALWAYS COME AFTER A TEMPERATURE INCREASE NOT BEFORE

Sceptic

ce-cores dating back nearly one million years show a pattern of temperature and CO2 rise at roughly 100,000-year intervals. But the CO2 rise has always come after the temperature rise, not before, presumably as warmer temperatures have liberated the gas from oceans.

Counter

This is largely true, but largely irrelevant. Ancient ice-cores do show CO2 rising after temperature by a few hundred years – a timescale associated with the ocean response to atmospheric changes mainly driven by wobbles in the Earth’s orbit. However, this time, CO2 is leading temperature. Furthermore, the situation today is dramatically different. The extra CO2 in the atmosphere (35% increase over pre-industrial levels) is from man-made emissions, and levels are higher than have been seen in 650,000 years of ice-core records.

8. LONG-TERM DATA ON HURRICANES AND ARCTIC ICE IS TOO POOR TO ASSESS TREN

Sceptic

Before the era of satellite observation began in the 1970s, measurements were ad-hoc and haphazard. Hurricanes would be reported only if they hit land or shipping. The extent of Arctic ice was measured only during expeditions. The satellite record for these phenomena is too short to justify claims that hurricanes are becoming stronger or more frequent, or that there is anything exceptional about the apparent shrinkage in Arctic ice up to 2007.

Counter

The Arctic Climate Impact Assessment project notes that systematic collection of data in parts of the Arctic began in the late 18th Century. The US National Hurricane Center notes that “organised reconnaissance” for Atlantic storms began in 1944. So although historical data is not as complete as one might like, conclusions can still be drawn from it. And the IPCC does not claim that global warming will make hurricanes more frequent – its 2007 report says that if anything, they are likely to become less frequent, but more intense.

9. WATER VAPOUR IS THE MAJOR GREENHOUSE GAS; CO2 IS RELATIVELY UNIMPORTANT

Sceptic

The natural greenhouse effect keeps the Earth’s surface about 33C warmer than it would otherwise be. Water vapour is the most important greenhouse gas, accounting for about 98% of all warming. So changes in carbon dioxide or methane concentrations would have a relatively small impact. Water vapour concentrations are rising, but this does not necessarily increase warming – it depends how the water vapour is distributed.

Counter

The statement that water vapour is “98% of the greenhouse effect” is simply false. In fact, it does about 50% of the work; clouds add another 25%, with CO2 and the other greenhouse gases contributing the remaining quarter. Water vapour concentrations are increasing in response to rising temperatures, and there is evidence that this is adding to warming, for example in Europe. The fact that water vapour is a feedback is included in all climate models.

10.PROBLEMS SUCH AS HIV/AIDS AND POVERTY ARE MORE PRESSING THAN CLIMATE CHANGE

Sceptic

he Kyoto Protocol has not reduced emissions of greenhouse gases noticeably. The targets were too low, applied only to certain countries, and have been rendered meaningless by loopholes. Many governments that enthuse about the treaty and want a successor are not going to meet the reduction targets that they signed up to in Kyoto. Even if it is real, man-made climate change is just one problem among many facing the world’s rich and poor alike. Governments and societies should respond proportionately, not pretend that climate is a special case. Poorer countries should not be forced to constrain their emissions and therefore their economic growth, as they will be under a Copenhagen treaty. Some economists believe that a warmer climate would, on balance, improve lives.

Counter

Arguments over the Kyoto Protocol are outside the realms of science, although it certainly has not reduced greenhouse gas emissions as far or as fast as the IPCC indicates is necessary. The latest IPCC Working Group 2 report suggest that the impact of man-made climate change will on balance be deleterious, particular to the poorer countries of the tropics, although colder regions may see benefits such as increased crop yields. Investment in energy efficiency, new energy technologies and renewables are likely to benefit the developing world. A Copenhagen treaty would not force emission constraints on the world’s poorest countries – in fact, it will funnel money to them for technology and climate protection, helping clean growth. More affluent developing countries – including China – will have to constrain their emissions growth but they agreed to this at the 2007 Bali summit

THE DEBATE CONTINUES ONLINE …….

A selection of web sites and blogs.

IPCC

UN climate convention

British Antarctic Survey

Climate Audit

Climatic Research Unit,

Nasa Goddard Institute for Space Studies

realclimate.org

Science and Environmental Policy Project

UK Met Office

Hadley Centre National Oceanic and Atmospheric Administration

UN Environment Programme data centre

US National Snow and Ice Data Center

World Meteorological Organization

Brave New Climate

Climate Change: The Next Generation

Climate Debate Daily

Climate Sanity

CO2 Science

Deltoid – global warming

Grist – climate and energy

James’ Empty Blog

Roger Pielke Jr.’s Blog

New Scientist – climate


2 thoughts on “Climate Change – the real truth?

  1. Hi

    I am the education manager for Practical Action, a charity that works with communities in developing countries supporting them in introducing sustainable technological solutions to improve their lives. I am currently improving our education resources for students in the UK, focusing on renewable energy and climate change. One of the areas that students look at in the curriculum is called ‘How science works’ where they have to evaluate arguments for and against issues such as climate change, taking into account the validity of the information they have. I think this article would be an excellent resource to support that and would like to signpost it.

    The only problem is in the section which looks at the sceptics point and the counter argument the right hand side of the text does not appear, it is as if a whole column has been blanked out. If would be much appreciated if this could be sorted out so that your article could be used by schoolchildren throughout the UK.

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