Four new papers discuss the relationship between solar activity andclimate

Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt..._calogovic.pdf
http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf

On 3/11/10 12:05 AM, Sam Wormley wrote:
Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt..._calogovic.pdf

http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf


http://www.realclimate.org/index.php...ons/#more-3007

The paper by Judith Lean (2010) has the character of a review article,
summarizing past studies on the relationship between solar forcing and
climate. The main message from her article is that the solar forcing
probably plays a modest role for the global warming over the last 100
years (10% or less). It’s a nice overview, but I miss treatment of
uncertainties.

Her analysis is based on the HadCRUT3 data, and I wonder if she would
get similar results if she chose the GISTEMP or NCDC instead. The choice
may in particular be relevant for the discussion of the temperatures
after 1998.

Personally, I regard the data on solar activity before 1900 as quite
uncertain too. The reason is that there are strange things happening to
the solar cycle length in the shift from the 19th to the 20th century.
Hence, any analysis based on the past centuries is uncertain because of
suspect data quality in the early part of the record. Lean mentions that
proxy-based records are uncertain, however.

Another source of uncertainty stems from the analysis itself – a
regression analysis with chaotic data can easily yield misleading
results. Gavin and I showed in a recent paper that multiple regression
can produce strange results when applied to the global mean temperature
and a number of forcings.

In other words, I think the reader may get the wrong impression from
Lean (2010) that the link between solar activity and climate is better
established than the data and methods suggest. Especially when she
discusses forecasts for the near future (eg. for year 2014) – I fear
that such a discussion can be misinterpreted and misused. However,
that’s my view, and it does not necessarily mean that her paper is
incorrect – quite the opposite, I think her main conclusions are sound
(Her estimate of the solar contribution to the global warming over past
century – 10% or less – is in good agreement with the figure Gavin and I
got in our analysis).

The positive side is that the paper is probably clearer and more
accessible without all these caveats. I also think she makes an
interesting point when she discusses ‘fundamental puzzles’ associated
with claims of strong solar role in terms of the past warming. She puts
this into the context of climate sensitivity, arguing that it would
imply that Earth’s climate be insensitive to well-measured increases in
GHG concentrations and simultaneously excessively sensitive to poorly
known solar brightness changes. Furthermore, Lean argues that it would
also require that the Sun’s brightness increased more in the past
century than at any time in the past millennium – a situation not
readily supported by observations.

The paper of Calogovic et al. (2010) is a follow-up of a recent paper by
Svensmark et al. (2009), looking into the claim that the cloud water
content drops after a Forbush event. Their work involved estimating
cosmic ray fluxes for the whole planet, and comparing it to local cloud
information derived from satellites. They concluded that the Forbush
events had no detectable effect on the clouds.

Moreover, they also argued that the analysis of Svensmark et al. (2009)
gave unreliable results since it included a Forbush event on January 20,
2005 which was accompanied by a strong solar proton event. However, they
did not explain explicitly why such proton events would disturb the
measurements, but referred to another study by Laken et al. (2009) in
Geophysical Research Letter. Laken et. al. only discusses the proton
events briefly, and refers to a study by Fluckiger et al. (2005), who
state that “The cosmic ray ground level enhancement (GLE) on January 20,
2005 is ranked among the largest in years, with neutron monitor count
rates increased by factors of more than 50″.

But there is no reference to proton events in Fluckiger et al. (2005),
so I’m not convinced that proton events will invalidate the analysis of
Svensmark et al. (2009). Perhaps I’m missing something? Anyway, this is
only a minor detail, and the rest of the analysis of Calogovic et al.
(2010) seems more convincing. Their conclusion is supported by Kulmala
et al. (2010): “galactic cosmic rays appear to play a minor role for
atmospheric aerosol formation events, and so for the connected
aerosol-climate effects as well�. Kulmala’s group in Finland boasts many
world-renowned aerosol physicists.

The study by Kulmala et al. (2010) was based on near-ground measurements
of aerosols, magnetic field, cosmic rays, sunlight intensity (solar
radiation), and ionization over a 13-year long period (~1 solar cycle).
They also used airborne Neutral cluster and Air Ion Spectrometer, LIDAR
and Forward Scattering Spectrometer Probe measurements. They failed to
detect any correlation between cosmic ray ionization intensity and
atmospheric aerosol formation.

Feulner and Rahmstorf address a speculation stated by Lean: the
possibility of solar forcing countering anthropogenic global warming.
Their paper examines the effect a solar grand minimum (low solar
activity similar to that inferred for the Maunder Minimum) would have on
the global mean temperature by 2100. By accounting for a corresponding
reduction in forcing for the future in a climate model study, they
conclude that the effect is negligible (less than 0.3K compared to 3.7 –
4.5K if the SRES A1b or A2 emission scenarios were assumed).

So what can we learn from these articles? What we see is how science
often works – increases in knowledge by increments and independent
studies re-affirming previous findings, namely that changes in the sun
play a minor role in climate change on decadal to centennial scales.
After all, 2009 was the second-warmest year on record, and by far the
warmest in the southern hemisphere, despite the record solar minimum.
The solar signal for the past 25 years is not just small but negative
(i.e. cooling), but this has not noticeably slowed down global warming.
But there are also many unknowns remaining, and the largest
uncertainties concern clouds, cloud physics, and their impact on
climate. In this sense, I find it ironic that some people still rely on
the cosmic rays argument as their strongest argument against AGW – it
does involve poorly known clouds physics!

On Mar 11, 1:12Â*am, Sam Wormley wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt...kationen/2010_...

http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf

http://www.realclimate.org/index.php...ore-on-sun-cli...

The paper by Judith Lean (2010) has the character of a review article,
summarizing past studies on the relationship between solar forcing and
climate. The main message from her article is that the solar forcing
probably plays a modest role for the global warming over the last 100
years (10% or less). It’s a nice overview, but I miss treatment of
uncertainties.

Her analysis is based on the HadCRUT3 data, and I wonder if she would
get similar results if she chose the GISTEMP or NCDC instead. The choice
may in particular be relevant for the discussion of the temperatures
after 1998.

Personally, I regard the data on solar activity before 1900 as quite
uncertain too. The reason is that there are strange things happening to
the solar cycle length in the shift from the 19th to the 20th century.
Hence, any analysis based on the past centuries is uncertain because of
suspect data quality in the early part of the record. Lean mentions that
proxy-based records are uncertain, however.

Another source of uncertainty stems from the analysis itself – a
regression analysis with chaotic data can easily yield misleading
results. Gavin and I showed in a recent paper that multiple regression
can produce strange results when applied to the global mean temperature
and a number of forcings.

In other words, I think the reader may get the wrong impression from
Lean (2010) that the link between solar activity and climate is better
established than the data and methods suggest. Especially when she
discusses forecasts for the near future (eg. for year 2014) – I fear
that such a discussion can be misinterpreted and misused. However,
that’s my view, and it does not necessarily mean that her paper is
incorrect – quite the opposite, I think her main conclusions are sound
(Her estimate of the solar contribution to the global warming over past
century – 10% or less – is in good agreement with the figure Gavin and I
got in our analysis).

The positive side is that the paper is probably clearer and more
accessible without all these caveats. I also think she makes an
interesting point when she discusses ‘fundamental puzzles’ associated
with claims of strong solar role in terms of the past warming. She puts
this into the context of climate sensitivity, arguing that it would
imply that Earth’s climate be insensitive to well-measured increases in
GHG concentrations and simultaneously excessively sensitive to poorly
known solar brightness changes. Furthermore, Lean argues that it would
also require that the Sun’s brightness increased more in the past
century than at any time in the past millennium – a situation not
readily supported by observations.

The paper of Calogovic et al. (2010) is a follow-up of a recent paper by
Svensmark et al. (2009), looking into the claim that the cloud water
content drops after a Forbush event. Their work involved estimating
cosmic ray fluxes for the whole planet, and comparing it to local cloud
information derived from satellites. They concluded that the Forbush
events had no detectable effect on the clouds.

Moreover, they also argued that the analysis of Svensmark et al. (2009)
gave unreliable results since it included a Forbush event on January 20,
2005 which was accompanied by a strong solar proton event. However, they
did not explain explicitly why such proton events would disturb the
measurements, but referred to another study by Laken et al. (2009) in
Geophysical Research Letter. Laken et. al. only discusses the proton
events briefly, and refers to a study by Fluckiger et al. (2005), who
state that “The cosmic ray ground level enhancement (GLE) on January 20,
2005 is ranked among the largest in years, with neutron monitor count
rates increased by factors of more than 50″.

But there is no reference to proton events in Fluckiger et al. (2005),
so I’m not convinced that proton events will invalidate the analysis of
Svensmark et al. (2009). Perhaps I’m missing something? Anyway, this is
only a minor detail, and the rest of the analysis of Calogovic et al.
(2010) seems more convincing. Their conclusion is supported by Kulmala
et al. (2010): “galactic cosmic rays appear to play a minor role for
atmospheric aerosol formation events, and so for the connected
aerosol-climate effects as well�. Kulmala’s group in Finland boasts many
world-renowned aerosol physicists.

The study by Kulmala et al. (2010) was based on near-ground measurements
of aerosols, magnetic field, cosmic rays, sunlight intensity (solar
radiation), and ionization over a 13-year long period (~1 solar cycle).
They also used airborne Neutral cluster and Air Ion Spectrometer, LIDAR
and Forward Scattering Spectrometer Probe measurements. They failed to
detect any correlation between cosmic ray ionization intensity and
atmospheric aerosol formation.

Feulner and Rahmstorf address a speculation stated by Lean: the
possibility of solar forcing countering anthropogenic global warming.
Their paper examines the effect a solar grand minimum (low solar
activity similar to that inferred for the Maunder Minimum) would have on
the global mean temperature by 2100. By accounting for a corresponding
reduction in forcing for the future in a climate model study, they
conclude that the effect is negligible (less than 0.3K compared to 3.7 –
4.5K if the SRES A1b or A2 emission scenarios were assumed).

So what can we learn from these articles? What we see is how science
often works – increases in knowledge by increments and independent
studies re-affirming previous findings, namely that changes in the sun
play a minor role in climate change on decadal to centennial scales.
After all, 2009 was the second-warmest year on record, and by far the
warmest in the southern hemisphere, despite the record solar minimum.
The solar signal for the past 25 years is not just small but negative
(i.e. cooling), but this has not noticeably slowed down global warming.
But there are also many unknowns remaining, and the largest
uncertainties concern clouds, cloud physics, and their impact on
climate. In this sense, I find it ironic that some people still rely on
the cosmic rays argument as their strongest argument against AGW – it
does involve poorly known clouds physics!

I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Uncle Ben

On 3/11/2010 9:30 AM, Uncle Ben wrote:
On Mar 11, 1:12 am, Sam wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt...kationen/2010_...

http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf

http://www.realclimate.org/index.php...ore-on-sun-cli...

The paper by Judith Lean (2010) has the character of a review article,
summarizing past studies on the relationship between solar forcing and
climate. The main message from her article is that the solar forcing
probably plays a modest role for the global warming over the last 100
years (10% or less). It’s a nice overview, but I miss treatment of
uncertainties.

Her analysis is based on the HadCRUT3 data, and I wonder if she would
get similar results if she chose the GISTEMP or NCDC instead. The choice
may in particular be relevant for the discussion of the temperatures
after 1998.

Personally, I regard the data on solar activity before 1900 as quite
uncertain too. The reason is that there are strange things happening to
the solar cycle length in the shift from the 19th to the 20th century.
Hence, any analysis based on the past centuries is uncertain because of
suspect data quality in the early part of the record. Lean mentions that
proxy-based records are uncertain, however.

Another source of uncertainty stems from the analysis itself – a
regression analysis with chaotic data can easily yield misleading
results. Gavin and I showed in a recent paper that multiple regression
can produce strange results when applied to the global mean temperature
and a number of forcings.

In other words, I think the reader may get the wrong impression from
Lean (2010) that the link between solar activity and climate is better
established than the data and methods suggest. Especially when she
discusses forecasts for the near future (eg. for year 2014) – I fear
that such a discussion can be misinterpreted and misused. However,
that’s my view, and it does not necessarily mean that her paper is
incorrect – quite the opposite, I think her main conclusions are sound
(Her estimate of the solar contribution to the global warming over past
century – 10% or less – is in good agreement with the figure Gavin and I
got in our analysis).

The positive side is that the paper is probably clearer and more
accessible without all these caveats. I also think she makes an
interesting point when she discusses ‘fundamental puzzles’ associated
with claims of strong solar role in terms of the past warming. She puts
this into the context of climate sensitivity, arguing that it would
imply that Earth’s climate be insensitive to well-measured increases in
GHG concentrations and simultaneously excessively sensitive to poorly
known solar brightness changes. Furthermore, Lean argues that it would
also require that the Sun’s brightness increased more in the past
century than at any time in the past millennium – a situation not
readily supported by observations.

The paper of Calogovic et al. (2010) is a follow-up of a recent paper by
Svensmark et al. (2009), looking into the claim that the cloud water
content drops after a Forbush event. Their work involved estimating
cosmic ray fluxes for the whole planet, and comparing it to local cloud
information derived from satellites. They concluded that the Forbush
events had no detectable effect on the clouds.

Moreover, they also argued that the analysis of Svensmark et al. (2009)
gave unreliable results since it included a Forbush event on January 20,
2005 which was accompanied by a strong solar proton event. However, they
did not explain explicitly why such proton events would disturb the
measurements, but referred to another study by Laken et al. (2009) in
Geophysical Research Letter. Laken et. al. only discusses the proton
events briefly, and refers to a study by Fluckiger et al. (2005), who
state that “The cosmic ray ground level enhancement (GLE) on January 20,
2005 is ranked among the largest in years, with neutron monitor count
rates increased by factors of more than 50″.

But there is no reference to proton events in Fluckiger et al. (2005),
so I’m not convinced that proton events will invalidate the analysis of
Svensmark et al. (2009). Perhaps I’m missing something? Anyway, this is
only a minor detail, and the rest of the analysis of Calogovic et al.
(2010) seems more convincing. Their conclusion is supported by Kulmala
et al. (2010): “galactic cosmic rays appear to play a minor role for
atmospheric aerosol formation events, and so for the connected
aerosol-climate effects as well�. Kulmala’s group in Finland boasts many
world-renowned aerosol physicists.

The study by Kulmala et al. (2010) was based on near-ground measurements
of aerosols, magnetic field, cosmic rays, sunlight intensity (solar
radiation), and ionization over a 13-year long period (~1 solar cycle).
They also used airborne Neutral cluster and Air Ion Spectrometer, LIDAR
and Forward Scattering Spectrometer Probe measurements. They failed to
detect any correlation between cosmic ray ionization intensity and
atmospheric aerosol formation.

Feulner and Rahmstorf address a speculation stated by Lean: the
possibility of solar forcing countering anthropogenic global warming.
Their paper examines the effect a solar grand minimum (low solar
activity similar to that inferred for the Maunder Minimum) would have on
the global mean temperature by 2100. By accounting for a corresponding
reduction in forcing for the future in a climate model study, they
conclude that the effect is negligible (less than 0.3K compared to 3.7 –
4.5K if the SRES A1b or A2 emission scenarios were assumed).

So what can we learn from these articles? What we see is how science
often works – increases in knowledge by increments and independent
studies re-affirming previous findings, namely that changes in the sun
play a minor role in climate change on decadal to centennial scales.
After all, 2009 was the second-warmest year on record, and by far the
warmest in the southern hemisphere, despite the record solar minimum.
The solar signal for the past 25 years is not just small but negative
(i.e. cooling), but this has not noticeably slowed down global warming.
But there are also many unknowns remaining, and the largest
uncertainties concern clouds, cloud physics, and their impact on
climate. In this sense, I find it ironic that some people still rely on
the cosmic rays argument as their strongest argument against AGW – it
does involve poorly known clouds physics!

I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Do _any_ of these models explain the approximately 100,000 year
glaciation cycle and why right now we appear to be at the warm peak of
that cycle? If they do not then they are missing something important.

Uncle Ben

HA ..rarely does Sam talk like this. But then again, maybe he copied it from
a real climate scientist. The crazy thing about climate science is that
ANYONE who is any kind of science type think they have an automatic claim to
doing and interpreting climate science. Sure ANY earth science type is free
to make opinions but that's all they are...opinions. It's really wierd when
an astrophysicist strickly by virtue of their title think they automatically
can be construed as a "climate scientist:".

I am certain a lot of grant money is going into the wrong hands.


"Uncle Ben" wrote in message
...
On Mar 11, 1:12 am, Sam Wormley wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt...kationen/2010_...

http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf

http://www.realclimate.org/index.php...ore-on-sun-cli...

The paper by Judith Lean (2010) has the character of a review article,
summarizing past studies on the relationship between solar forcing and
climate. The main message from her article is that the solar forcing
probably plays a modest role for the global warming over the last 100
years (10% or less). It's a nice overview, but I miss treatment of
uncertainties.

Her analysis is based on the HadCRUT3 data, and I wonder if she would
get similar results if she chose the GISTEMP or NCDC instead. The choice
may in particular be relevant for the discussion of the temperatures
after 1998.

Personally, I regard the data on solar activity before 1900 as quite
uncertain too. The reason is that there are strange things happening to
the solar cycle length in the shift from the 19th to the 20th century.
Hence, any analysis based on the past centuries is uncertain because of
suspect data quality in the early part of the record. Lean mentions that
proxy-based records are uncertain, however.

Another source of uncertainty stems from the analysis itself - a
regression analysis with chaotic data can easily yield misleading
results. Gavin and I showed in a recent paper that multiple regression
can produce strange results when applied to the global mean temperature
and a number of forcings.

In other words, I think the reader may get the wrong impression from
Lean (2010) that the link between solar activity and climate is better
established than the data and methods suggest. Especially when she
discusses forecasts for the near future (eg. for year 2014) - I fear
that such a discussion can be misinterpreted and misused. However,
that's my view, and it does not necessarily mean that her paper is
incorrect - quite the opposite, I think her main conclusions are sound
(Her estimate of the solar contribution to the global warming over past
century - 10% or less - is in good agreement with the figure Gavin and I
got in our analysis).

The positive side is that the paper is probably clearer and more
accessible without all these caveats. I also think she makes an
interesting point when she discusses 'fundamental puzzles' associated
with claims of strong solar role in terms of the past warming. She puts
this into the context of climate sensitivity, arguing that it would
imply that Earth's climate be insensitive to well-measured increases in
GHG concentrations and simultaneously excessively sensitive to poorly
known solar brightness changes. Furthermore, Lean argues that it would
also require that the Sun's brightness increased more in the past
century than at any time in the past millennium - a situation not
readily supported by observations.

The paper of Calogovic et al. (2010) is a follow-up of a recent paper by
Svensmark et al. (2009), looking into the claim that the cloud water
content drops after a Forbush event. Their work involved estimating
cosmic ray fluxes for the whole planet, and comparing it to local cloud
information derived from satellites. They concluded that the Forbush
events had no detectable effect on the clouds.

Moreover, they also argued that the analysis of Svensmark et al. (2009)
gave unreliable results since it included a Forbush event on January 20,
2005 which was accompanied by a strong solar proton event. However, they
did not explain explicitly why such proton events would disturb the
measurements, but referred to another study by Laken et al. (2009) in
Geophysical Research Letter. Laken et. al. only discusses the proton
events briefly, and refers to a study by Fluckiger et al. (2005), who
state that "The cosmic ray ground level enhancement (GLE) on January 20,
2005 is ranked among the largest in years, with neutron monitor count
rates increased by factors of more than 50?.

But there is no reference to proton events in Fluckiger et al. (2005),
so I'm not convinced that proton events will invalidate the analysis of
Svensmark et al. (2009). Perhaps I'm missing something? Anyway, this is
only a minor detail, and the rest of the analysis of Calogovic et al.
(2010) seems more convincing. Their conclusion is supported by Kulmala
et al. (2010): "galactic cosmic rays appear to play a minor role for
atmospheric aerosol formation events, and so for the connected
aerosol-climate effects as well". Kulmala's group in Finland boasts many
world-renowned aerosol physicists.

The study by Kulmala et al. (2010) was based on near-ground measurements
of aerosols, magnetic field, cosmic rays, sunlight intensity (solar
radiation), and ionization over a 13-year long period (~1 solar cycle).
They also used airborne Neutral cluster and Air Ion Spectrometer, LIDAR
and Forward Scattering Spectrometer Probe measurements. They failed to
detect any correlation between cosmic ray ionization intensity and
atmospheric aerosol formation.

Feulner and Rahmstorf address a speculation stated by Lean: the
possibility of solar forcing countering anthropogenic global warming.
Their paper examines the effect a solar grand minimum (low solar
activity similar to that inferred for the Maunder Minimum) would have on
the global mean temperature by 2100. By accounting for a corresponding
reduction in forcing for the future in a climate model study, they
conclude that the effect is negligible (less than 0.3K compared to 3.7 -
4.5K if the SRES A1b or A2 emission scenarios were assumed).

So what can we learn from these articles? What we see is how science
often works - increases in knowledge by increments and independent
studies re-affirming previous findings, namely that changes in the sun
play a minor role in climate change on decadal to centennial scales.
After all, 2009 was the second-warmest year on record, and by far the
warmest in the southern hemisphere, despite the record solar minimum.
The solar signal for the past 25 years is not just small but negative
(i.e. cooling), but this has not noticeably slowed down global warming.
But there are also many unknowns remaining, and the largest
uncertainties concern clouds, cloud physics, and their impact on
climate. In this sense, I find it ironic that some people still rely on
the cosmic rays argument as their strongest argument against AGW - it
does involve poorly known clouds physics!

I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Uncle Ben

Bonehead is always on the side to the trolls.

"Mick Love" wrote in message
news:Il9mn.67848$Db2.61012@edtnps83...
HA ..rarely does Sam talk like this. But then again, maybe he copied it
from a real climate scientist. The crazy thing about climate science is
that ANYONE who is any kind of science type think they have an automatic
claim to doing and interpreting climate science. Sure ANY earth science
type is free to make opinions but that's all they are...opinions. It's
really wierd when an astrophysicist strickly by virtue of their title
think they automatically can be construed as a "climate scientist:".

I am certain a lot of grant money is going into the wrong hands.


"Uncle Ben" wrote in message
...
On Mar 11, 1:12 am, Sam Wormley wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate: one by Judith Lean (2010) in WIREs Climate Change, a GRL paper
by Calogovic et al. (2010), Kulmala et al. (2010), and an on-line
preprint by Feulner and Rahmstorf (2010). They all look at different
aspects of how changes in solar activity may influence our climate.

http://wires.wiley.com/WileyCDA/Wire...sId-WCC18.html
http://www.eawag.ch/organisation/abt...kationen/2010_...

http://www.atmos-chem-phys.net/10/18...1885-2010.html
http://www.agu.org/journals/gl/gl100...10GL042710.pdf

http://www.realclimate.org/index.php...ore-on-sun-cli...

The paper by Judith Lean (2010) has the character of a review article,
summarizing past studies on the relationship between solar forcing and
climate. The main message from her article is that the solar forcing
probably plays a modest role for the global warming over the last 100
years (10% or less). It's a nice overview, but I miss treatment of
uncertainties.

Her analysis is based on the HadCRUT3 data, and I wonder if she would
get similar results if she chose the GISTEMP or NCDC instead. The choice
may in particular be relevant for the discussion of the temperatures
after 1998.

Personally, I regard the data on solar activity before 1900 as quite
uncertain too. The reason is that there are strange things happening to
the solar cycle length in the shift from the 19th to the 20th century.
Hence, any analysis based on the past centuries is uncertain because of
suspect data quality in the early part of the record. Lean mentions that
proxy-based records are uncertain, however.

Another source of uncertainty stems from the analysis itself - a
regression analysis with chaotic data can easily yield misleading
results. Gavin and I showed in a recent paper that multiple regression
can produce strange results when applied to the global mean temperature
and a number of forcings.

In other words, I think the reader may get the wrong impression from
Lean (2010) that the link between solar activity and climate is better
established than the data and methods suggest. Especially when she
discusses forecasts for the near future (eg. for year 2014) - I fear
that such a discussion can be misinterpreted and misused. However,
that's my view, and it does not necessarily mean that her paper is
incorrect - quite the opposite, I think her main conclusions are sound
(Her estimate of the solar contribution to the global warming over past
century - 10% or less - is in good agreement with the figure Gavin and I
got in our analysis).

The positive side is that the paper is probably clearer and more
accessible without all these caveats. I also think she makes an
interesting point when she discusses 'fundamental puzzles' associated
with claims of strong solar role in terms of the past warming. She puts
this into the context of climate sensitivity, arguing that it would
imply that Earth's climate be insensitive to well-measured increases in
GHG concentrations and simultaneously excessively sensitive to poorly
known solar brightness changes. Furthermore, Lean argues that it would
also require that the Sun's brightness increased more in the past
century than at any time in the past millennium - a situation not
readily supported by observations.

The paper of Calogovic et al. (2010) is a follow-up of a recent paper by
Svensmark et al. (2009), looking into the claim that the cloud water
content drops after a Forbush event. Their work involved estimating
cosmic ray fluxes for the whole planet, and comparing it to local cloud
information derived from satellites. They concluded that the Forbush
events had no detectable effect on the clouds.

Moreover, they also argued that the analysis of Svensmark et al. (2009)
gave unreliable results since it included a Forbush event on January 20,
2005 which was accompanied by a strong solar proton event. However, they
did not explain explicitly why such proton events would disturb the
measurements, but referred to another study by Laken et al. (2009) in
Geophysical Research Letter. Laken et. al. only discusses the proton
events briefly, and refers to a study by Fluckiger et al. (2005), who
state that "The cosmic ray ground level enhancement (GLE) on January 20,
2005 is ranked among the largest in years, with neutron monitor count
rates increased by factors of more than 50?.

But there is no reference to proton events in Fluckiger et al. (2005),
so I'm not convinced that proton events will invalidate the analysis of
Svensmark et al. (2009). Perhaps I'm missing something? Anyway, this is
only a minor detail, and the rest of the analysis of Calogovic et al.
(2010) seems more convincing. Their conclusion is supported by Kulmala
et al. (2010): "galactic cosmic rays appear to play a minor role for
atmospheric aerosol formation events, and so for the connected
aerosol-climate effects as well". Kulmala's group in Finland boasts many
world-renowned aerosol physicists.

The study by Kulmala et al. (2010) was based on near-ground measurements
of aerosols, magnetic field, cosmic rays, sunlight intensity (solar
radiation), and ionization over a 13-year long period (~1 solar cycle).
They also used airborne Neutral cluster and Air Ion Spectrometer, LIDAR
and Forward Scattering Spectrometer Probe measurements. They failed to
detect any correlation between cosmic ray ionization intensity and
atmospheric aerosol formation.

Feulner and Rahmstorf address a speculation stated by Lean: the
possibility of solar forcing countering anthropogenic global warming.
Their paper examines the effect a solar grand minimum (low solar
activity similar to that inferred for the Maunder Minimum) would have on
the global mean temperature by 2100. By accounting for a corresponding
reduction in forcing for the future in a climate model study, they
conclude that the effect is negligible (less than 0.3K compared to 3.7 -
4.5K if the SRES A1b or A2 emission scenarios were assumed).

So what can we learn from these articles? What we see is how science
often works - increases in knowledge by increments and independent
studies re-affirming previous findings, namely that changes in the sun
play a minor role in climate change on decadal to centennial scales.
After all, 2009 was the second-warmest year on record, and by far the
warmest in the southern hemisphere, despite the record solar minimum.
The solar signal for the past 25 years is not just small but negative
(i.e. cooling), but this has not noticeably slowed down global warming.
But there are also many unknowns remaining, and the largest
uncertainties concern clouds, cloud physics, and their impact on
climate. In this sense, I find it ironic that some people still rely on
the cosmic rays argument as their strongest argument against AGW - it
does involve poorly known clouds physics!

I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Uncle Ben

Uncle Ben wrote:

On Mar 11, 1:12*am, Sam Wormley wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate
snip
I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Amen to that. Thank you, Sam.
--
Dave

Must be from KOOKamunga


"Dave Typinski" wrote in message
...
Uncle Ben wrote:

On Mar 11, 1:12 am, Sam Wormley wrote:
On 3/11/10 12:05 AM, Sam Wormley wrote:

Four new papers discuss the relationship between solar activity and
climate
snip
I was wondering why I continue to follow this kook-infested newsgroup.
Sam, your posts make it worth the effort.

Amen to that. Thank you, Sam.
--
Dave