advisory re locally available Godiva Safe Sea Sunblock 50; a simple guide regarding climate change controversies

Advisory re locally available Godiva Safe Sea Sunblock 50, which was advertised as allegedly "the WORLD'S ONLY sunblock
with jellyfish sting protection." on page D1 of the April 25, 2008 issue of the Manila Bulletin newspaper. Before believing said claim, it will benefit portential users of said product to require the local distributor of said product to provide certification from an unbiased, independent entity that said product does provide jellyfish sting protection.


http://royalsociety.org/page.asp?id=6229
Climate change controversies: a simple guide

Climate change controversies

The Royal Society has produced this overview of the current state of scientific understanding of climate change to help non-experts better understand some of the debates in this complex area of science.

This is not intended to provide exhaustive answers to every contentious argument that has been put forward by those who seek to distort and undermine the science of climate change and deny the seriousness of the potential consequences of global warming. Instead, the Society - as the UK's national academy of science - responds here to eight key arguments that are currently in circulation by setting out, in simple terms, where the weight of scientific evidence lies.


* Misleading argument 1 : The Earth's climate is always changing and this is
nothing to do with humans.

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.


* Misleading argument 2 : 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).


* Misleading argument 3 : 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.



* Misleading argument 4 : 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.


* Misleading argument 5 : 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.


* Misleading argument 6 : 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


* Misleading argument 7 : 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.


* Misleading argument 8 : 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


our scientific understanding of climate change is sufficiently sound to make us highly confident that greenhouse gas emissions are causing global warming. Science moves forward by challenge and debate and this will continue. However, none of the current criticisms of climate science, nor the alternative explanations of global warming are well enough founded to make not taking any action the wise choice. The science clearly points to the need for nations to take urgent steps to cut greenhouse gas emissions into the atmosphere, as much and as fast as possible, to reduce the more severe aspects of climate change. We must also prepare for the impacts of climate change, some of which are already inevitable.


This document was compiled with the help of the Royal Society Climate Change Advisory Group and other leading experts.

April 2007