Here is my response to the Lockwood Paper. Comments are welcome.
Mike
Lockwood and Claus Frohlich published a paper in the Proceedings of
the Royal Society which concludes that the Sun could not be responsible
for the global temperature rise over the last twenty years. The BBC
published a news story on the paper dated July 10, 2007.
Cosmic rays vary over an 11 year cycle with the sunspot cycle. Dr.
Svensmark developed a theory that the Sun is a significant driver of
climate change through its effects on the cosmic ray flux and cloud
cover. The increased solar wind and magnetic field during times of high
sunspot count repels cosmic rays that otherwise would hit the Earth's
atmosphere, resulting is less aerosols in the lower atmosphere and
thereby reducing low cloud formation. Fewer low clouds allows more
solar radiation to reach the Earth's surface causing warming.
The BBC article presents this graphic:
![Lockwook Cosmic Connection](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.2&filename=Lockwood_cosmic_conn_.gif)
The BBC article is misleading because the graph titled "Cosmic ray
count" is not of cosmic rays (neutrons) count at all. It is the result
of a mathematical manipulation to eliminate 11 year cosmic ray cycle.
The curve is taken from the Lockwood paper. The actual cosmic ray
count from the Climax neutron monitor is shown as the blue curve below.
![Cosmic rya intensity and Sunspot number](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.3)
Note that the cosmic ray count shown above is identical to that given
in the Svensmark paper shown below. The red curve shown below is the
cosmic ray count variation. The blue line shows variations in global
cloud cover.
![Svenmark Cosmic ray](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.4)
The Lockwood paper is fundamentally flawed for several reasons.
The paper states "Hence, all solar trends since 1987 have been in the
opposite direction to those seen or inferred in the majority of the
twentieth century—particularly in the first half of that century".
This is not true for cosmic rays which shows very low counts during the
1990-1991 solar maximum; lower counts than the previous three cycles.
This would have cause warming during the 1990's.
The paper states "The Earth’s surface air temperature (figure 1e) does
not respond to the solar cycle."
This is false; the earth temperature does respond to the solar cycle as
confirmed by numerous studies. The 11 year solar cycle is clearly
shown in sediment
cores obtained from Effington Inlet, Vancouver Island, B.C., and in
records of the Nile
River, to name just two studies.
The paper continues with "Even a large amplitude modulation would be
heavily damped in the global
mean temperature record by the long thermal time constants associated
with parts of the climate system, in particular the oceans (Wigley
& Raper 1990)."
This is true. The oceans act as a hugh climate flywheel, which both
smoothes and delays the effects of the climate forcings. Global
temperatures do not react strongly to each 11 year cycle, but are
smoothed out. Here is the World 1970 - 2006 land and sea-surface
temperature data from hadCRUT3 database.
![1970-2006 World Temp HadCRUT3](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.5)
You can clearly see that when the cosmic ray
counts are high,
there is a temperature drop, 1974-77, 1986-87, 1995-97, and 2004 -
2006.
The pink straight line best fit indicates 0.1880 Celsius per decade.
The Lockwood paper manipulates the cosmic ray count data to eliminate
the 11 year cycle by extrapolating between the nodes of the cycles. The
nodes are points where the top part of the cycle has the same mean as
the lower part, approximately the midpoint of each cycle. The result is
the "Cosmic ray count" graph shown in the BBC article and reproduced
above. Note that this reveals a 22 year cycle. But totally eliminating
the 11 year cycle implies that the damping effect of the oceans is near
infinite, which would also eliminate a 22 year cycle, or any other
cycle length. If the oceans really had a near infinite heat capacity,
it would absorb all effects of the Sun and CO2 changes and
global temperatures would not change! Lockwood essentially applies a
100% damping to the 11 year cycle but 0% damping to the 22 year cycle,
which is complete nonsense.
The ocean's flywheel damping effect means that the temperature today is
effected by the Suns activity over the last many years. The 2006 global
temperature is effected mostly by the 2006 Sun's intensity, but also by
the Sun's activity in previous years. Even the Sun's activity 20 years
ago has an effect on the current temperature.
Below is a graph showing a hypothetical increase followed by a decrease
in the Sun's forcing, and the resulting temperature change. The graph
is only for illustrative purposes to show the climate smoothing and
time lag effects on temperature. The units are arbitrary. Here I assume
the temperature of a given year is effected by the Sun's forcing over
the previous 24 years such that each prior year has 85% of the
weighting of the next year.
![Climate Smoothing](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.6&filename=Climate_smoothing.jpg)
Note that the temperature continues to rise for several years after the
Sun's forcing starts to decrease.
The Lockwood paper falsely assumes that the current Sun activity would
have an immediate effect on temperature without a time lag. One should
expect a time lag based on the length of the variation cycle. For
example, each day the Sun's intensity peaks at noon but daily
temperatures peak several hours later. Each year the Sun's intensity
peaks at June 21, but July and August are the warmest months in the
northern hemisphere.
The 11 year solar cycle causes about a 2 year lag in the temperature
variation. The Sun's activity has been increasing though most of the
twentieth century and one should expect about a decade of time lag. The
graph below from here
show the rising solar flux during most of the twentieth century.
![Solar Fluc](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.7&filename=nir3-Solar_flux.jpg)
Since the cosmic ray count was a minimum in 1991 (the 2001-2002 minimum
count was higher) we expect the temperature to increase for about a
decade to about 2001 before falling. This is exactly what has happened!
All climatologists should know the the heat capacity of the oceans
cause a large time lag in temperature response. The IPCC fourth
assessment report includes computer model projections that show if the
CO2 concentration is held constant at year 2000 levels, the global
temperature will continue to rise over the next two decades. The same
effect occurs for Sun activity as CO2.
Lockwood compares the cosmic ray (with the 11 year cycle removed) to a
smoothed surface temperature graph. The Sun's climate forcings should
be compared to the actual temperature curves, which show no increase in
global temperatures since 2002.
The surface temperatures used by Lockwood are contaminated by the heat
island effects and numerous quality control issues related to the
individual station measurements and spatial placements. Lockwood should
use the MSU (Microwave Sounding Units) satellite data which is truly a
global measure of temperatures, as it is the troposphere temperature,
and is not contaminated by the heat island effect.
The theory of CO2 temperature change shows that the enhanced greenhouse
effect would increase temperatures faster in the troposphere where
temperatures are cold and the water vapour content is low. All the
climate models show that the troposphere temperatures should increase
faster than the surface temperatures, especially in the tropics.
The graph below shows the temperature in the tropics.
![Temperature Trends in the Tropics](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.8&filename=Surface%20and%20Troposphere%20Temperature.gif)
The three curves are scaled so that the average of the first 5 years
are the same. The GHCN curve is the land only surface temperature
trend. It shows the highest rate of increase because it is contaminated
by the heat island effect. The HadCRUT3 curve is the land and sea
surface temperature trend. It is lower that the GHCN curve because the
sea temperature data does not have any heat island effect. If the Sun
had little effect on climate and CO2 was responsible for the twentieth
century temperature rise, both of these curves should show a lower
warming trend than the MSU, troposphere temperature, curve! It is
illogical to believe that CO2 is the primary temperature driver and
concurrently believe that the surface measurements are accurate.
The Lockwood paper only analysis the last 30 years of data which is too
short of a time interval. A system that has 11 year cycles require at
least 110 years (10 cycles) of data to obtain meaningful statistical
results.
The paper says in the conclusions "... there was a detectable influence
of solar variability in the first half of the twentieth century". The
BBC article quote Lockwood "It [the cosmic ray effect] might even have
had a significant effect on pre-industrial climate; but you cannot
apply it to what we're seeing now, because we're in a completely
different ball game." The paper fails to explain what laws of physics
have recently changed.
Solar activity correlates well with temperature
over longer time scales. The graph below from Scafetta and West of
Duke University compares solar proxies with the Northern hemisphere
temperature reconstruction by Moberg et al. [2005].
![400 years Temperature and Sun](mailbox-message://nobody@local%20folders/Inbox#405765197?header=saveas&part=1.9&filename=400yearSolarSignature.jpg)
Solar activity can account for at least 50% of the warming since 1900.
It is likely that both the Sun/Cosmic rays and CO2 emissions are
affecting climate.
In summary, the Lockwood paper is seriously flawed by:
- It falsely says the Sun's influence peaked by 1987. The cosmic
ray count in 1991 is the lowest it has ever been, causing warming.
- It falsely says the Earth's temperature does not respond to solar
cycles.
- It eliminates the 11 year solar cycle from the cosmic ray data,
but does not smooth any other cycle.
- It fails to account for the large time lag between the Sun
forcings and temperature changes.
- It uses smoothed surface temperatures rather than actual global
satellite temperature data.
- It analyses too short a time interval
- It fails to explain why the cosmic ray influence apparently
stopped twenty years ago.
This paper is so flawed that it is remarkable that it was published.
My conclusion is that the recent Sun and cosmic ray data is entirely
consistent with the Friends of Science position that the Sun is the
primary driver of climate change.