GSA Changes Its Position: Now Agrees Global Warming Caused By Human Activity
Harry Hope
http://www.geosociety.org/positions/position10.htm
Climate Change
Adopted in October 2006; revised April 2010
Position Statement
Decades of scientific research have shown that climate can change from
both natural and anthropogenic causes.
The Geological Society of America (GSA) concurs with assessments by
the National Academies of Science (2005), the National Research
Council (2006), and the Intergovernmental Panel on Climate Change
(IPCC, 2007) that global climate has warmed and that human activities
(mainly greenhouse-gas emissions) account for most of the warming
since the middle 1900s.
If current trends continue, the projected increase in global
temperature by the end of the twentyfirst century will result in large
impacts on humans and other species.
Addressing the challenges posed by climate change will require a
combination of adaptation to the changes that are likely to occur and
global reductions of CO2 emissions from anthropogenic sources.
Purpose
This position statement
(1) summarizes the strengthened basis for the conclusion that humans
are a major factor responsible for recent global warming;
(2) describes the large effects on humans and ecosystems if
greenhouse-gas concentrations and global climate reach projected
levels; and
(3) provides information for policy decisions guiding mitigation and
adaptation strategies designed to address the future impacts of
anthropogenic warming.
Scientific advances in the first decade of the 21st century have
greatly reduced previous uncertainties about the amplitude and causes
of recent global warming.
Ground-station measurements have shown a warming trend of ~0.7 °C
since the mid-1800s, a trend consistent with
(1) retreat of northern hemisphere snow and Arctic sea ice in the last
40 years;
(2) greater heat storage in the ocean over the last 50 years; (3)
retreat of most mountain glaciers since 1850;
(4) an ongoing rise of global sea level for more than a century; and
(5) proxy reconstructions of temperature change over past centuries
from ice cores, tree rings, lake sediments, boreholes, cave deposits
and corals. Both instrumental records and proxy indices from geologic
sources show that global mean surface temperature was higher during
the last few decades of the 20th century than during any comparable
period during the preceding four centuries (National Research Council,
2006).
Measurements from satellites, which began in 1979, initially did not
show a warming trend, but later studies (Mears and Wentz, 2005; Santer
et al., 2008) found that the satellite data had not been fully
adjusted for losses of satellite elevation through time, differences
in time of arrival over a given location, and removal of
higher-elevation effects on the lower tropospheric signal.
With these factors taken into account, the satellite data are now in
basic agreement with ground-station data and confirm a warming trend
since 1979.
In a related study, Sherwood et al. (2005) found problems with
corrections of tropical daytime radiosonde measurements and largely
resolved a previous discrepancy with ground-station trends.
With instrumental discrepancies having been resolved, recent warming
of Earth’s surface is now consistently supported by a wide range of
measurements and proxies and is no longer open to serious challenge.
The geologic record contains unequivocal evidence of former climate
change, including periods of greater warmth with limited polar ice,
and colder intervals with more widespread glaciation.
These and other changes were accompanied by major shifts in species
and ecosystems.
Paleoclimatic research has demonstrated that these major changes in
climate and biota are associated with significant changes in climate
forcing such as continental positions and topography, patterns of
ocean circulation, the greenhouse gas composition of the atmosphere,
and the distribution and amount of solar energy at the top of the
atmosphere caused by changes in Earth's orbit and the evolution of the
sun as a main sequence star.
Cyclic changes in ice volume during glacial periods over the last
three million years have been correlated to orbital cycles and changes
in greenhouse gas concentrations, but may also reflect internal
responses generated by large ice sheets.
This rich history of Earth's climate has been used as one of several
key sources of information for assessing the predictive capabilities
of modern climate models.
The testing of increasingly sophisticated climate models by comparison
to geologic proxies is continuing, leading to refinement of hypotheses
and improved understanding of the drivers of past and current climate
change.
Given the knowledge gained from paleoclimatic studies, several
long-term causes of the current warming trend can be eliminated.
Changes in Earth’s tectonism and its orbit are far too slow to have
played a significant role in a rapidly changing 150-year trend.
At the other extreme, large volcanic eruptions have cooled global
climate for a year or two, and El Niño episodes have warmed it for
about a year, but neither factor dominates longer-term trends.
As a result, greenhouse gas concentrations, which can be influenced by
human activities, and solar fluctuations are the principal remaining
factors that could have changed rapidly enough and lasted long enough
to explain the observed changes in global temperature.
Although the 3rd IPCC report allowed that solar fluctuations might
have contributed as much as 30% of the warming since 1850, subsequent
observations of Sun-like stars (Foukal et al., 2004) and new
simulations of the evolution of solar sources of irradiance variations
(Wang et al., 2005) have reduced these estimates.
The 4th (2007) IPCC report concluded that changes in solar irradiance,
continuously measured by satellites since 1979, account for less than
10% of the last 150 years of warming.
Greenhouse gases remain as the major explanation.
Climate model assessments of the natural and anthropogenic factors
responsible for this warming conclude that rising anthropogenic
emissions of greenhouse gases have been an increasingly important
contributor since the mid-1800s and the major factor since the
mid-1900s (Meehl et al., 2004).
The CO2 concentration in the atmosphere is now ~30% higher than peak
levels that have been measured in ice cores spanning 800,000 years of
age, and the methane concentration is 2.5 times higher.
About half of Earth’s warming has occurred through the basic
heat-trapping effect of the gases in the absence of any feedback
processes.
This “clear-sky” response to climate is known with high certainty.
The other half of the estimated warming results from the net effect of
feedbacks in the climate system:
a very large positive feedback from water vapor;
a smaller positive feedback from snow and ice albedo;
and sizeable, but still uncertain, negative feedbacks from clouds and
aerosols.
The vertical structure of observed changes in temperature and water
vapor in the troposphere is consistent with the anthropogenic
greenhouse-gas “fingerprint” simulated by climate models (Santer et
al., 2008).
Considered in isolation, the greenhouse-gas increases during the last
150 years would have caused a warming larger than that actually
measured, but negative feedback from clouds and aerosols has offset
part of the warming.
In addition, because the oceans take decades to centuries to respond
fully to climatic forcing, the climate system has yet to register the
full effect of gas increases in recent decades.
These advances in scientific understanding of recent warming form the
basis for projections of future changes.
If greenhouse-gas emissions follow the current trajectory, by 2100
atmospheric CO2 concentrations will reach two to four times
pre-industrial levels, for a total warming of less than 2 °C to more
than 5 °C compared to 1850.
This range of changes in greenhouse gas concentrations and temperature
would substantially alter the functioning of the planet in many ways.
The projected changes involve risk to humans and other species:
(1) continued shrinking of Arctic sea ice with effects on native
cultures and ice-dependent biota;
(2) less snow accumulation and earlier melt in mountains, with
reductions in spring and summer runoff for agricultural and municipal
water;
(3) disappearance of mountain glaciers and their late-summer runoff;
(4) increased evaporation from farmland soils and stress on crops;
(5) greater soil erosion due to increases in heavy convective summer
rainfall;
(6) longer fire seasons and increases in fire frequency;
(7) severe insect outbreaks in vulnerable forests;
(8) acidification of the global ocean; and
(9) fundamental changes in the composition, functioning, and
biodiversity of many terrestrial and marine ecosystems.
In addition, melting of Greenland and West Antarctic ice (still highly
uncertain as to amount), along with thermal expansion of seawater and
melting of mountain glaciers and small ice caps, will cause
substantial future sea-level rise along densely populated coastal
regions, inundating farmland and dislocating large populations.
Because large, abrupt climatic changes occurred within spans of just
decades during previous ice-sheet fluctuations, the possibility exists
for rapid future changes as ice sheets become vulnerable to large
greenhouse-gas increases.
Finally, carbon-climate model simulations indicate that 10–20% of the
anthropogenic CO2 “pulse” could stay in the atmosphere for thousands
of years, extending the duration of fossil-fuel warming and its
effects on humans and other species.
The acidification of the global ocean and its effects on ocean life
are projected to last for tens of thousands of years.
Public Policy Aspects
Recent scientific investigations have strengthened the case for policy
action to reduce greenhouse gas emissions and to adapt to unavoidable
climate change.
To strengthen the consensus for action, this statement from the
Geological Society of America is intended to inform policymakers about
improved knowledge of Earth’s climate system based on advances in
climate science.
Recent scientific investigations have contributed to this improved
understanding of the climate system and supplied strong evidence for
human-induced global warming, providing policy makers with a unique
perspective on which to base mitigation and adaptation strategies.
Carefully researched and tested adaptation strategies can both reduce
and limit negative impacts and explore potential positive impacts.
Future climate change will pose societal, biological, economic, and
strategic challenges that will require a combination of national and
international emissions reductions and adaptations.
These challenges will also require balanced and thoughtful national
and international discussions leading to careful long-term planning
and sustained policy actions.
Recommendations
Public policy should include effective strategies for the reduction of
greenhouse gas emissions.
Cost-effective investments to improve the efficient use of Earth’s
energy resources can reduce the economic impacts of future adaptation
efforts.
Strategies for reducing greenhouse-gas emissions should be evaluated
based on their impacts on climate, on costs to global and national
economies, and on positive and negative impacts on the health, safety
and welfare of humans and ecosystems.
Comprehensive local, state, national and international planning is
needed to address challenges posed by future climate change.
Near-, mid-, and long-term strategies for mitigation of, and
adaptation to climate change should be developed, based in part on
knowledge gained from studies of previous environmental changes.
Public investment is needed to improve our understanding of how
climate change affects society, including on local and regional
scales, and to formulate adaptation measures.
Sustained support of climate-related research to advance understanding
of the past and present operation of the climate system is needed,
with particular focus on the major remaining uncertainties in
understanding and predicting Earth’s future climate at regional and
global scales.
Research is needed to improve our ability to assess the response and
resilience of natural and human systems to past, present, and future
changes in the climate system.
Opportunities for GSA and GSA Members to Help
Implement Recommendations
To facilitate implementation of the goals of this position statement,
the Geological Society of America recommends that its members take the
following actions:
Actively participate in professional education and discussion
activities to be technically informed about the latest advances in
climate science.
GSA should encourage symposia at regional, national and international
meetings to inform members on mainstream understanding among
geoscientists and climate scientists of the causes and future effects
of global warming within the broader context of natural variability.
These symposia should seek to actively engage members in hosted
discussions that clarify issues, possibly utilizing educational
formats other than the traditional presentation and Q&A session.
Engage in public education activities in the community, including the
local level. Public education is a critical element of a proactive
response to the challenges presented by global climate change.
GSA members are encouraged to take an active part in outreach
activities to educate the public at all levels (local, regional,
national, and international) about the science of global warming and
the importance of geological research in framing policy development.
Such activities can include organizing and participating in community
school activities;
leading discussion groups in civic organizations;
meeting with local and state community leaders and congressional
staffs;
participating in GSA’s Congressional Visits Day;
writing opinion pieces and letters to the editor for local and
regional newspapers; contributing to online forums;
and volunteering for organizations that support efforts to mitigate
and adapt to global climate change.
Collaborate with a wide range of stakeholders and help educate and
inform them about the causes and impacts of global climate change from
the geosciences perspective.
GSA members are encouraged to discuss with businesses and policy
makers the science of global warming, as well as opportunities for
transitioning from our predominant dependence on fossil fuels to
greater use of low-carbon energies and energy efficiencies.
Work interactively with other science and policy societies to help
inform the public and ensure that policymakers have access to
scientifically reliable information.
GSA should actively engage and collaborate with other earth-science
organizations in recommending and formulating national and
international strategies to address impending impacts of anthropogenic
climate change.
Take advantage of the following list of references for
a current scientific assessment of global climate change.
REFERENCES CITED
National Reports
IPCC (Intergovernmental Panel on Climate Change), 2007, Summary for
policymakers, in Climate Change 2007: The physical science basis:
Cambridge, United Kingdom, Cambridge University Press, 18 p.
National Academies of Science (2005). Joint academes statement: Global
response to climate change.
(http://nationalacademies.org/onpi/06072005.pdf)
National Research Council, 2006, Surface temperature reconstructions
for the last 2000 years: Washington, D.C., National Academy Press, 146
p.
Peer-Reviewed Articles
Foukal, P.G., et al., 2004, A stellar view on solar variations and
climate: Science, v. 306, p. 68–69.
Mears, C.A., and Wentz, F.J., 2005, The effect of diurnal correction
on satellite-derived lower tropospheric temperature: Science online,
doi: 10.1126/science.1114772.
Meehl et al., 2004, Combinations of natural and anthropogenic forcings
in twentieth-century climate: J. of Climate, v. 17, p. 3721-3727.
Santer, B., et al., 2008, Consistency of modeled and observed
temperature trends in the tropical troposphere: International Journal
of Climatology, v. 28, p. 1703–1722.
Sherwood, S., Lanzante, J., and Meyer, C., 2005, Radiosonde biases and
late-20th century warming: Science online, doi:
10/1126/science.1115640.
Wang, Y.-M., Lean, J.L., and Sheeley, N.R. Jr., 2005, Modeling the
Sun’s magnetic field and irradiance since 1713: Astrophysical Journal,
v. 625, p. 522–538.
SELECTED WEB SITES
Intergovernmental Panel on Climate Change
IPCC reports: www.ipcc.ch/
U.S. National Academies
Climate Change at the National Academies: dels.nas.edu/climatechange/
Surface temperature reconstructions:
www.nap.edu/catalog.php?record_id=11676#toc
U.S. Global Change Research Program
Home page: www.globalchange.gov/
Satellite issue:
www.climatescience.gov/Library/sap/sap1-1/finalreport/default.htm
Geologic record of abrupt changes:
www.climatescience.gov/Library/sap/sap3-4/final-report/
Global climate change impacts in the United States:
www.globalchange.gov./publications/reports/scientific-assessments/us-impacts©
The Geological Society of America
Giga2
> http://www.geosociety.org/positions/position10.htm
>
Just in time for the collapse and subsequent humiliation, clever move,
lol.
leona...@gmail.com
> http://www.geosociety.org/positions/position10.htm
>
> Climate Change
>
> Adopted in October 2006; revised April 2010
>
> Position Statement
>
> Decades of scientific research have shown that climate can change from
> both natural and anthropogenic causes.
>
> The Geological Society of America (GSA) concurs with assessments by
> the National Academies of Science (2005), the National Research
> Council (2006), and the Intergovernmental Panel on Climate Change
> (IPCC, 2007) that global climate has warmed and that human activities
> (mainly greenhouse-gas emissions) account for most of the warming
> since the middle 1900s.
>
> If current trends continue, the projected increase in global
> temperature by the end of the twentyfirst century will result in large
> impacts on humans and other species.
Ø Political trash — no science whatsoever.
— —
| In real science the burden of proof is always
| on the proposer, never on the skeptics. So far
| neither IPCC nor anyone else has provided one
| iota of valid data for global warming nor have
| they provided data that climate change is being
| effected by commerce and industry, and not by
| natural causes
Dawlish
wrote:
>
> - Show quoted text -
Well, it would be "stupidly" wouldn't it? I mean, the organisation is
jam packed full of scientists, for goodness sake! Stupid scientists,
obviously. *>))
Sid9
<leona...@gmail.com> wrote in message
news:05148e2c-fc9e-4957...@l6g2000vbo.googlegroups.com...
.
Ayn Rand didn’t believe scientists that smoking cigarettes causes lung
cancer.
Ayn Rand died of lung cancer.
We don’t need no stinkin' scientists!
leona...@gmail.com
> <leonard7...@gmail.com> wrote in message
Ø Where is the proof that it was caused by smoking???
leona...@gmail.com
> Well, it would be "stupidly" wouldn't it? I mean, the organisation is
> jam packed full of scientists, for goodness sake! Stupid scientists,
> obviously. *>))
Ø Nnnnnaaaaaaaahh! Those that wrote that were
old bureaucratic hacks following the government
line.
Dawlish
>
> - Show quoted text -
Not scientists then?
Giga2
> <leonard7...@gmail.com> wrote in message
Rand underwent surgery for lung cancer in 1974. Several more of her
closest associates parted company with her,[62] and during the late
1970s her activities within the Objectivist movement declined,
especially after the death of her husband on November 9, 1979.[63] One
of her final projects was work on a television adaptation of Atlas
Shrugged. She had also planned to write another novel, but did not get
far in her notes.[64] Rand died of heart failure on March 6, 1982 at
her home in New York City
http://en.wikipedia.org/wiki/Ayn_Rand#Atlas_Shrugged_and_later_years