50 reasons why global warming isn't natural
Michael Le Page, features editor
A British newspaper today published a list of "100 reasons why global warming is natural".
Here we take a quick look at the first 50 of their claims - and debunk each one.
<br /><br /><b>1)</b> <i>There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man's activity.</i><br /><br />Technically, <a href="http://en.wikipedia.org/wiki/Science">proof exists only in mathematics</a>, not in science. Whatever terminology you choose to use, however, there is overwhelming evidence that the current warming is caused by <a href="http://www.newscientist.com/blog/environment/2007/05/climate-myths-special.html">the rise in greenhouse gases due to human activities</a>. <br /><br /><b>2)</b> <i>Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 per cent of the total naturally emitted from the mantle of the Earth during geological history.<br /></i><br />Misleading comparison. Since the industrial age began <a href="http://www.newscientist.com/article/dn11638">human emissions are far higher than volcanic emissions</a>. <br /><br /><b>3)</b> <i>Warmer periods of the Earth's history came around 800 years before rises in CO<sub>2</sub> levels</i>.<br /><br />In the past 3 million years changing levels of sunshine triggered and ended the ice ages. Carbon dioxide was a feedback that increased warming, rather than the initial cause. In the more distant past, <a href="http://www.newscientist.com/article/dn11659">several warming episodes were directly triggered by CO<sub>2</sub></a>. <br /><br /><b>4)</b> <i>After world war 2, there was a huge surge in recorded CO<sub>2</sub> emissions but global temperatures fell for four decades after 1940</i>.<br />
<br />
In fact, temperatures fell during the 1940s and then remained roughly level until the late 1970s. The fall was partly due to high levels of pollutants such as sulphur dioxide counteracting the warming effect.<br />
<br />
<b>5) </b><i>Throughout the Earth's history, temperatures have often been warmer
than now and CO<sub>2</sub> levels have often been higher - more than 10 times as
high.</i><br />
<br />
Which shows that higher CO<sub>2</sub> means higher temperatures, taking into
account the fact that the sun was cooler in the past. The crucial point is that <a href="http://www.newscientist.com/article/dn11647">civilisation is adapted to 20th century temperatures</a>. <br />
<br />
<b>6)</b> <i>Significant changes in climate have continually occurred throughout geologic time.</i><br /><br />
<a href="http://www.newscientist.com/article/dn11647">Yes</a>. And sea level has been up to 70 metres higher during warm periods.
If that happens again, there'll be no more London or New York. <br />
<br />
<b>7) </b><i>The 0.7 °C increase in the average global temperature over the past
hundred years is entirely consistent with well-established, long-term,
natural climate trends.</i> <br /><br />
Wrong. The rapid warming since the late 1970s has occurred <a href="http://www.newscientist.com/article/dn11650">even though
other factors that can warm the planet, such as the sun's intensity,
have remained constant</a>. <br />
<br />
<br />
<b>8)</b> <i>The IPCC theory is driven by just 60 scientists and favourable reviewers, not the 4000 usually cited.</i><br /><br />
Untrue, as even the briefest look at the scientific literature can establish.<br />
<br />
<b>9) </b><i>Leaked e-mails from British climate scientists - in a scandal known
as "climategate" - suggest that that has been manipulated to
exaggerate global warming</i><br />
<br /><a href="http://www.newscientist.com/article/dn18238">Nothing in the emails undermines any of the key scientific conclusions</a>.
Independent groups have come to the same conclusions. <br />
<br />
<b>10)</b> <i>A large body of scientific research suggests that the sun is
responsible for the greater share of climate change during the past
hundred years.</i><br /><br />
The sun may have contributed to the warming in the first part of the
20th century but <a href="http://www.newscientist.com/article/dn11650">it has not caused the rapid warming since the late
1970s</a>. <br />
<br />
<b>11)</b> <i>Politicians and activists claim rising sea levels are a direct
cause of global warming, but sea levels have been increasing
steadily since the last ice age 10,000 years ago.</i><br /><br />
Wrong. Sea level rose very rapidly as the North American ice sheet
melted after the last ice age but levelled off and has been nearly
stable for the past 2000 years or so. <a href="http://www.newscientist.com/article/mg20327151.300">Now it is starting to rise
rapidly again</a>. <br />
<b><br />
12)</b> <i>Philip Stott, emeritus professor of biogeography at the School of
Oriental and African Studies in London says climate change is too
complicated to be caused by just one factor, whether CO<sub>2</sub> or clouds.</i><br /><br />
He is right. All sorts of factors affect climate, even the lead in
petrol. However, the recent warming is <a href="http://www.newscientist.com/article/dn11462">mostly due to rising greenhouse
gases</a>, and if we pump out more CO<sub>2</sub> it will get even hotter. <br />
<br />
<b>13)</b> <i>Peter Lilley MP said last month that "fewer people in Britain than
in any other country believe in the importance of global warming. That
is despite the fact that our government and our political
class - predominantly - are more committed to it than their counterparts in
any other country in the world".</i><br /><br />
Irrelevant and incorrect on all counts.<br />
<br />
<b>14)</b> <i>In pursuit of the global warming rhetoric, wind farms will do very little to nothing to reduce CO<sub>2</sub> emissions.</i><br /><br />
There are arguments over how much wind power can contribute, but there
is no doubt they are <a href="http://www.newscientist.com/article/mg18825253.400">already helping reduce emissions in
many countries</a>. <br />
<br />
<b>15) </b><i>Professor Plimer, professor of geology and earth sciences at the
University of Adelaide, stated that the idea of taking a single trace
gas in the atmosphere, accusing it and finding it guilty of total
responsibility for climate change, is an "absurdity".</i><br /><br />
See (1). And note that Plimer is a geologist, not a climatologist. <br />
<b><br />
16)</b> <i>A Harvard University astrophysicist and geophysicist, <a href="http://en.wikipedia.org/wiki/Willie_Soon">Willie Soon</a>,
said he is "embarrassed and puzzled" by the shallow science in papers
that support the proposition that the Earth faces a climate crisis
caused by global warming.</i><br /><br />
Many scientists think Soon should be embarrassed by <a href="http://www.newscientist.com/article/dn18279">some
of the papers he has published</a>. <br />
<br />
<b>17)</b> <i>The science of what determines the Earth's temperature is in fact far from settled or understood.</i><br /><br />
There are still lots of details to fill in but the big picture is
increasingly clear. The uncertainties that do exist <a href="http://www.realclimate.org/index.php/archives/2009/12/unsettled-science/">swing both ways</a>:
there could be more warming than predicted.
<br />
<br />
<b>18)</b> <i>Despite activist concerns over CO<sub>2</sub> levels, CO<sub>2</sub> is a minor greenhouse gas, unlike water vapour, which is tied to climate concerns,
and which we can't even pretend to control.</i><br /><br />
Water vapour is a feedback, <a href="http://www.newscientist.com/article/dn11652">not a cause of warming</a>. The amount of water in the atmosphere depends on temperature; any excess rains out within days. <br />
<br />
<b>19) </b><i>A petition by scientists trying to tell the world that the political and media portrayal of global warming is false was put forward in the Heidelberg Appeal in 1992. Today, more than 4000 signatories, including 72 Nobel prizewinners, from 106 countries have signed it.</i><br /><br />
That's <a href="http://en.wikipedia.org/wiki/Heidelberg_Appeal">not what the Heidelberg Appeal really said</a>, and 1992 was a long time ago.<br />
<br />
<b>20)</b> <i>It is claimed the average global temperature increased at a
dangerously fast rate in the 20th century but the recent rate of
average global temperature rise has been between 1 and 2 °C per
century - within natural rates.</i><br /><br />
Incorrect. Over the past 1000 years <a href="http://www.newscientist.com/article/dn11644">temperature has never changed nearly as fast</a>. <br />
<br />
Michael Le Page, features editor
A British newspaper today published a list of "100 reasons why global warming is natural".
Here we take a quick look at the first 50 of their claims - and debunk each one.
<br /><br /><b>1)</b> <i>There is "no real scientific proof" that the current warming is caused by the rise of greenhouse gases from man's activity.</i><br /><br />Technically, <a href="http://en.wikipedia.org/wiki/Science">proof exists only in mathematics</a>, not in science. Whatever terminology you choose to use, however, there is overwhelming evidence that the current warming is caused by <a href="http://www.newscientist.com/blog/environment/2007/05/climate-myths-special.html">the rise in greenhouse gases due to human activities</a>. <br /><br /><b>2)</b> <i>Man-made carbon dioxide emissions throughout human history constitute less than 0.00022 per cent of the total naturally emitted from the mantle of the Earth during geological history.<br /></i><br />Misleading comparison. Since the industrial age began <a href="http://www.newscientist.com/article/dn11638">human emissions are far higher than volcanic emissions</a>. <br /><br /><b>3)</b> <i>Warmer periods of the Earth's history came around 800 years before rises in CO<sub>2</sub> levels</i>.<br /><br />In the past 3 million years changing levels of sunshine triggered and ended the ice ages. Carbon dioxide was a feedback that increased warming, rather than the initial cause. In the more distant past, <a href="http://www.newscientist.com/article/dn11659">several warming episodes were directly triggered by CO<sub>2</sub></a>. <br /><br /><b>4)</b> <i>After world war 2, there was a huge surge in recorded CO<sub>2</sub> emissions but global temperatures fell for four decades after 1940</i>.<br />
<br />
In fact, temperatures fell during the 1940s and then remained roughly level until the late 1970s. The fall was partly due to high levels of pollutants such as sulphur dioxide counteracting the warming effect.<br />
<br />
<b>5) </b><i>Throughout the Earth's history, temperatures have often been warmer
than now and CO<sub>2</sub> levels have often been higher - more than 10 times as
high.</i><br />
<br />
Which shows that higher CO<sub>2</sub> means higher temperatures, taking into
account the fact that the sun was cooler in the past. The crucial point is that <a href="http://www.newscientist.com/article/dn11647">civilisation is adapted to 20th century temperatures</a>. <br />
<br />
<b>6)</b> <i>Significant changes in climate have continually occurred throughout geologic time.</i><br /><br />
<a href="http://www.newscientist.com/article/dn11647">Yes</a>. And sea level has been up to 70 metres higher during warm periods.
If that happens again, there'll be no more London or New York. <br />
<br />
<b>7) </b><i>The 0.7 °C increase in the average global temperature over the past
hundred years is entirely consistent with well-established, long-term,
natural climate trends.</i> <br /><br />
Wrong. The rapid warming since the late 1970s has occurred <a href="http://www.newscientist.com/article/dn11650">even though
other factors that can warm the planet, such as the sun's intensity,
have remained constant</a>. <br />
<br />
<br />
<b>8)</b> <i>The IPCC theory is driven by just 60 scientists and favourable reviewers, not the 4000 usually cited.</i><br /><br />
Untrue, as even the briefest look at the scientific literature can establish.<br />
<br />
<b>9) </b><i>Leaked e-mails from British climate scientists - in a scandal known
as "climategate" - suggest that that has been manipulated to
exaggerate global warming</i><br />
<br /><a href="http://www.newscientist.com/article/dn18238">Nothing in the emails undermines any of the key scientific conclusions</a>.
Independent groups have come to the same conclusions. <br />
<br />
<b>10)</b> <i>A large body of scientific research suggests that the sun is
responsible for the greater share of climate change during the past
hundred years.</i><br /><br />
The sun may have contributed to the warming in the first part of the
20th century but <a href="http://www.newscientist.com/article/dn11650">it has not caused the rapid warming since the late
1970s</a>. <br />
<br />
<b>11)</b> <i>Politicians and activists claim rising sea levels are a direct
cause of global warming, but sea levels have been increasing
steadily since the last ice age 10,000 years ago.</i><br /><br />
Wrong. Sea level rose very rapidly as the North American ice sheet
melted after the last ice age but levelled off and has been nearly
stable for the past 2000 years or so. <a href="http://www.newscientist.com/article/mg20327151.300">Now it is starting to rise
rapidly again</a>. <br />
<b><br />
12)</b> <i>Philip Stott, emeritus professor of biogeography at the School of
Oriental and African Studies in London says climate change is too
complicated to be caused by just one factor, whether CO<sub>2</sub> or clouds.</i><br /><br />
He is right. All sorts of factors affect climate, even the lead in
petrol. However, the recent warming is <a href="http://www.newscientist.com/article/dn11462">mostly due to rising greenhouse
gases</a>, and if we pump out more CO<sub>2</sub> it will get even hotter. <br />
<br />
<b>13)</b> <i>Peter Lilley MP said last month that "fewer people in Britain than
in any other country believe in the importance of global warming. That
is despite the fact that our government and our political
class - predominantly - are more committed to it than their counterparts in
any other country in the world".</i><br /><br />
Irrelevant and incorrect on all counts.<br />
<br />
<b>14)</b> <i>In pursuit of the global warming rhetoric, wind farms will do very little to nothing to reduce CO<sub>2</sub> emissions.</i><br /><br />
There are arguments over how much wind power can contribute, but there
is no doubt they are <a href="http://www.newscientist.com/article/mg18825253.400">already helping reduce emissions in
many countries</a>. <br />
<br />
<b>15) </b><i>Professor Plimer, professor of geology and earth sciences at the
University of Adelaide, stated that the idea of taking a single trace
gas in the atmosphere, accusing it and finding it guilty of total
responsibility for climate change, is an "absurdity".</i><br /><br />
See (1). And note that Plimer is a geologist, not a climatologist. <br />
<b><br />
16)</b> <i>A Harvard University astrophysicist and geophysicist, <a href="http://en.wikipedia.org/wiki/Willie_Soon">Willie Soon</a>,
said he is "embarrassed and puzzled" by the shallow science in papers
that support the proposition that the Earth faces a climate crisis
caused by global warming.</i><br /><br />
Many scientists think Soon should be embarrassed by <a href="http://www.newscientist.com/article/dn18279">some
of the papers he has published</a>. <br />
<br />
<b>17)</b> <i>The science of what determines the Earth's temperature is in fact far from settled or understood.</i><br /><br />
There are still lots of details to fill in but the big picture is
increasingly clear. The uncertainties that do exist <a href="http://www.realclimate.org/index.php/archives/2009/12/unsettled-science/">swing both ways</a>:
there could be more warming than predicted.
<br />
<br />
<b>18)</b> <i>Despite activist concerns over CO<sub>2</sub> levels, CO<sub>2</sub> is a minor greenhouse gas, unlike water vapour, which is tied to climate concerns,
and which we can't even pretend to control.</i><br /><br />
Water vapour is a feedback, <a href="http://www.newscientist.com/article/dn11652">not a cause of warming</a>. The amount of water in the atmosphere depends on temperature; any excess rains out within days. <br />
<br />
<b>19) </b><i>A petition by scientists trying to tell the world that the political and media portrayal of global warming is false was put forward in the Heidelberg Appeal in 1992. Today, more than 4000 signatories, including 72 Nobel prizewinners, from 106 countries have signed it.</i><br /><br />
That's <a href="http://en.wikipedia.org/wiki/Heidelberg_Appeal">not what the Heidelberg Appeal really said</a>, and 1992 was a long time ago.<br />
<br />
<b>20)</b> <i>It is claimed the average global temperature increased at a
dangerously fast rate in the 20th century but the recent rate of
average global temperature rise has been between 1 and 2 °C per
century - within natural rates.</i><br /><br />
Incorrect. Over the past 1000 years <a href="http://www.newscientist.com/article/dn11644">temperature has never changed nearly as fast</a>. <br />
<br />
