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Summary of Hill Briefings on Global Climate Change (7-14-00)

As the second congressional session proceeds, both scientific and political aspects of global climate change continue to be issues of debate and concern.  While major legislative action has yet to take place, briefings for Hill staffers are held quite frequently.  To help inform congressional staffers about the science involved in the climate change issue, the U.S. Global Change Research Program (USGCRP) holds regular briefings, many of which are summarized below.

Alternative Approaches to Reducing Greenhouse Gas Emissions Through "Cap and Trade" Programs

The Dirksen Senate Office Building was the setting for this debate on the pros and cons of an "upstream" versus "downstream" domestic greenhouse gas emissions market, and an economy versus sector-by-sector market approach in reducing greenhouse gas emissions in the United States.  The debate was hosted by the Progressive Policy Institute, Center for Clean Air Policy, and Sky Trust.  Rep. John Porter (R-IL) was in attendance of the debate, moderated by Sue Gander, Senior Policy Analyst for the Center for Clean Air Policy.  Panelists included Carlton Bartels, Cantor Fitzgerald Brokerage; Paul Cicio, Dow Chemical; Jennifer Morgan, World Wildlife Fund; and Richard Morgenstern, Resources for the Future (RFF).

Rep. Porter opened the forum by remarking that there needs to be a system in place in order to hold those responsible for emitting greenhouse gases accountable.  He also stated that progress needs to be made on the climate change issue and should be a focus in the next session of Congress.

Richard Morgenstern, Senior Fellow, Quality of the Environment Division at RFF proposed that a domestic carbon emissions cap and trading system could be fully implemented by 2007.  He stated that such a system would include: 1) broad coverage, 2) a modest goal in cost containment, and 3) equitable burden sharing.  He stated that using an "upstream" approach, where carbon enters the system would be easier, more efficient, and would avoid unfair competition.  He stated that a capping permit price of $25 per ton of carbon would be introduced with a 7% increase per year.  In order to prevent permit prices from becoming extaordinarily high and stifling competition and innovation at the upstream level, Morgenstern stated a mechanism would be put in place to allow for the purchase of additional permits if a substantial increase in market demand deems necessary.  He proposed that permits would be auctioned off in the Department of Treasury.  Money would then be pooled and distributed by a transparent formula where 75% will go to U.S. residents and 25% to industries that may be negligibly impacted by the cap and trade system.

Paul Cicio spoke as a representative for the International Federation of Industrial Energy Consumers (IFIEC).  His main concern was how the reduction of carbon into the atmosphere would be implemented while retaining competitiveness between companies.  He stated that he likes a "downstream" economy-wide system that would let consumers ultimately decide.  Imported products--similar to domestically produced products--should be adjusted for at the border in order to compensate for lack of carbon controls outside of the U.S. and to retain competitiveness.

Carlton Bartels stated that a cap and trade system of $25 per ton of carbon at the "upstream" level is insignificant and looks to him as essentially a tax.  He estimated that such a system would probably increase cost to the consumer of fuel products by nearly $100 per year and would do little to deter consumption of high carbon emitting products.  He stated that fuel prices are too inelastic and that all you have to do is look outside and see all the gas guzzling SUVs on the road to prove this point.  He stated that caps on cost stifle innovation and that he favors a cap and trade system in the middle or at the manufacturing level.

Jennifer Morgan stated that she favors an "upstream" economy-wide approach to limiting the emissions of carbon into the atmosphere.  The system must be comprehensive, mandatory and must make dramatic changes while still allowing for flexibility.  Such a system, she continued, must also be economically efficient and have a high level of certainty in monitoring.  She stated that data-collection monitoring technologies of carbon dioxide emissions are highly developed and should be sufficient enough to fully implement a cap and trade system on that particular greenhouse gas.  She also stipulated that an offset mechanism should also be put into place so that innovation does not become compromised.  (7/11/00)


  Climate Warming of the 20th Century in the Context of Historical and Geological Records of Past Climate Changes

In its June 14th briefing, the U.S. Global Change Research Program (USGCRP) presented current
climate warming in both relative historical and geological terms.  Texas A & M University's Dr. Thomas J. Crowley spent most of his talk on climate changes since A.D. 1000, examining both the Little Ice Age (A.D. 1580-1880) and the Medieval Warm Period (~A.D. 1000) with respect to contemporary climate.  Drawing upon his own models as well as those of Jones and Mann, Crowley finds that, contrary to popular scientific opinion, the Medieval Warm Period was, at best, as warm as mid-20th century temperatures.  The current climate is warmer than that encountered by the Vikings a millennium ago, Crowley concludes.  In fact, "business as usual" projections from the Intergovenmental Panel on Climate Change (IPCC) and others indicate that twenty-first century global temperatures may be as warm or warmer than those of the last interglacial, making this century the warmest in the past 200,000 - 400,000 years.

Crowley devoted a large portion of his presentation to natural, climatic variability, exploring the relationship between that variability and his energy balance model.  When one speaks about global temperature increases, Crowley cautioned, he/she must remember that such increases are not uniformly distributed.   During the early Medieval Warm Period (A.D. 965-990), for instance, Greenland and Sweden were warmer than other areas of the Northern Hemisphere (a classic jet stream pattern) while later in the warm period (A.D. 1160-1180) the North Atlantic was warmer, a pattern strikingly similar to the North Atlantic Oscillation seen today.  Although the eleven-year solar cycle may play a small role in such decadal-scale climate changes, Crowley postulated, it is insignificant compared to volcanic forcing.  Using the Greenland ice cores' [SO42-] record, Crowley is confident that one can accurately evaluate pre-industrial volcanic activity.  Together, changes in the sun's energy output and pulses of volcanic activity account for much of the paleoclimate record between A.D. 1000 and A.D. 1850.  Neither of these mechanisms, nor ocean-atmosphere interactions, can account for late twentieth century warmth, however, although recent warmth is consistent with model projections based on greenhouse gas forcing.

A number of related issues came to the fore during the question and answer period.  One individual raised an objection to Crowley's mixing of mechanical data (post-1850) with paleodata, asserting that such intermingling may prejudice Crowley's claims.  In response to cries that mid-troposphere data do not support his climate warming hypothesis, Crowley retorted that such variability, like the atmospheric circulation changes during the Medieval Warm Period, is to be expected with a natural system.  Another audience member then asked Crowley about land clearing's role in greenhouse gas emissions.  Crowley admitted that land clearing is "tricky," a possible culprit for some of his model's problems (6/14/00).

The Record of Surface Warming in the 20th Century: Recent Observations and Model Results

An April 12th briefing held by the U.S. Global Change Research Project (USGCRP) focused on observed variability and trends in the Earth's surface temperatures during the last several hundred years.  Dr. Henry Pollack, from the University of Michigan, presented evidence of rising surface temperatures over the past 5 centuries.  From borehole temperature data, he deduced that the mean temperature of the earth's surface has increased by at least 1.8 degrees Fareinheight in the last 500 years, and that half of that warming has occurred during the 20th century alone.  Pollack also said that 80% of that warming occurred after the year 1800.  The second speaker was David Easterling, a principal scientist at NOAA's National Climatic Data Center in Asheville, NC.  Easterling noted that 1997, 1998, and 1999, are the three warmest years on record.  He also pointed out a 16-month streak in 1997 and 1998 where the record warm monthly global temperature was broke every month.  Easterling said that statistically, the likelihood of having this long stint of warm months is very low, and that some sort of factors other than natural variability must have been part of the picture.  The third speaker, Tom Knuston from NOAA's Geophysical Fluid Dynamics Laboratory, discussed whether current computer models can reproduce the recent surface temperature changes.  He showed that while both global averages and latitudinally-averaged temperatures for various latitudes were both reasonably accurate, smaller scale regional temperature patterns are not easily reproduced.  A more in-depth summary of the briefing is available on the USGCRP website.  (4/12/00)

How a Domestic Greenhouse Gas Emissions Trading Market Could Work in Practice

The Progressive Policy Institute (PPI) held a forum on emissions trading and global warming on Friday, March 3rd in the Capitol building.  Sen. Joseph Lieberman, (D-CT) who sponsored an early emissions crediting bill (S. 547) with the late Sen. John Chaffee (R-RI), made some opening remarks regarding whether he will reintroduce a bill this Congress.  He noted that, most likely, no legislative action will be taken.  Lieberman, instead, threw his support behind several proposals in the Clinton Administration's FY 2001 budget that are aimed at reducing greenhouse gas emissions.  Support for these measures might help to generate an emissions bill next year (Environment and Energy Daily, 3-6-00).

Speakers at the forum presented two main approaches to domestic emissions trading and greenhouse gas credits.  Jon Naimon, with Light Green Advisors, presented a plan that he co-authored with Debra Knopman, the Director of PPI's Center for Innovation & the Environment. PPI's plan would implement a plan similar to the procedures currently used by the Environmental Protection Agency's Toxics Release Inventory for reporting chemical releases.  Greenhouse gas emitters would submit information to the government and to an independently operated greenhouse gas emissions market exchange.  Emitters would be subject to penalties if the information is found incorrect through spot audits led by the government or through legal actions brought on by citizens.  An alternate plan, presented by Ray Kopp from Resources for the Future (RFF), would be an "upstream" program that controls fossil fuels inputs to the economy.  This would involve a smaller number of entities  --  coal producers and crude petroleum companies  --  than the PPI plan, which involves all emitters of greenhouse gases.  Both plans call for the federal government to allocate credits initially,  and then slowly phasing in an auctioning system.  The RFF plan calls for an initial price cap on credits of $25/ton of carbon released.  (3/3/00)

Climate Change in the Arctic and Antarctic: The Latest Observational Evidence on Changes in Sea Ice and Ice Shelves

The depletion of Arctic and Antarctic sea ice and sea ice shelves was the subject of a February 28th briefing held by the USGCRP  --  hosted by Jack Kaye Director of the Research Division of the Office of Earth Science of NASA.

Dr. Claire Parkinson of NASA's Goddard Space Flight Center showed satellite images of sea ice coverage that dated back to October 1978.  When the strong seasonal cycle is dampened, the satellite record shows a negative trend in total Arctic sea ice coverage. This negative trend in the average yearly sea ice coverage is apparent in seven out of nine regions of the Arctic.  In seasonal sea ice regions, where sea ice is only present for a portion of the year, there is a negative trend in the length of the sea ice season.  Evidence presented by Dr. D. Andrew Rothrock  --  from the Applied Physics Laboratory in the School of Oceanography at the University of Washington  --  complemented Parkinson's presentation by showing that the vertical thickness of the sea ice is also plummeting.  Rothrock combined data collected from U.S. Navy submarines that carry upward-looking sonars with topographic models of the upper surface of the the ice to determine ice thickness.  According to this data, the sea ice in the Arctic Ocean has decreased in thickness from an average of around 3 meters to less that 2 meters since the 1950s.  An article written by Rothrock is available on the web in both html and pdf formats.  Both Rothrock and Parkinson noted that the depletion of sea ice is neither temporally or spatially uniform.  While Rothrock admitted that the actual cause of these changes is not known, he listed several possible causes:

Parkinson pointed out that a decrease in sea ice reduces the insulation between the ocean and the atmosphere, allowing more heat to escape from the water.  She also noted ice reflects solar radiation back to space, therefore a decrease in ice would encourage further warming by retaining more radiation within the Earth system.

The third speaker, Dr. Ted Scambos, from the National Snow and Ice Center at the University of Colorado, Boulder, discussed ice shelf breakups in the Antarctic Peninsula.  Scambos showed aerial views of the Larson ice shelves, located on the Antarctic Peninsula, which is located south of the tip of South America.  He said that several features are related to rapid ice shelf retreat:

Scambos noted that that creation of melt ponds is particularly important because it enhances fracturing near the shear margins of the ice and near the ice front.  The length of the melt season has increased in the 1990's, resulting in a larger area of ice covered by melt ponds.

The question and answers session of this briefing consisted of questions pertaining to the causes and effects of global warming.  Some attendees questioned whether loss of sea ice is actually a result of overall global warming, and whether this warming is caused by anthropogenic sources or natural climatic fluctuations.  Others asked about the economic benefits of sea ice depletion.  Both the speakers and attendees of the briefing recognized that loss of sea ice would cause a huge loss of habitat for many species such as the polar bear.  (2/28/00)

What's Driving Climate Change in the 20th Century-Changes in Solar Radiation or the Buildup of Greenhouse Gases?

On November 23rd, the USGCRP held a briefing titled "The Role of the Sun in Climate Change".  The speakers were Dr. Judith Lean, of the Naval Research Laboratory's Space Science Division, and Dr. Jerry Mahlman, Director of NOAA's Geophysical Fluid Dynamics Laboratory. They presented evidence that changes in solar radiation output alone cannot explain the global warming that has taken place in the last century.  They also said that the recent warming trend can be explained by a combination of green-house gases increase and natural variability, or a combination of green-house gases and increased solar irradiance.  A synopsis of the presentation can be found on the USGRP website.  (11/23/99)

Sensitivity of the Tropics to a Global Climate Warming: Evidence and Implications

A Hill briefing titled "Sensitivity of the Tropics to a Global Climate Warming:  Evidence and Implications", was held by the USGCRP on November 16th.  Speakers Alan Mix, a professor of Oceanic and Atmospheric Science at Oregon State University, and Lonnie Thompson, a professor of Geosciences and a research scientist at the Byrd Polar Research Center at Ohio State University, gave presentations about tropical climate data collected from deep-sea sediments and glacial ice cores, respectively.  The evidence presented by both speakers implied that contrary to the commonly accepted belief that tropical regions are generally insensitive to climate changes, both tropical sea temperatures and glaciers are drastically affected by regional and global changes in climate.  Furthermore, changes in climate in the tropics and sub-tropics may actually initiate climate changes near the Earth's poles.  An overview of the lecture can be found at  (11/16/99)

Aviation and the Global Atmosphere

A lunchtime briefing, held by the USGCRP on October 26, 1999, addressed the recently released Intergovernmental Panel on Climate Change  (IPCC) report:  "Aviation and the Global Atmosphere."  Scientists and industrial representatives presented evidence about the contribution of airplanes to greenhouse gases in the upper atmosphere and answered questions about how emissions might change in the future.  While acknowledging and agreeing with the theory that increased concentrations of greenhouse gases will cause some climate change, some speakers tended to downplay aviation's contribution. Michael Prather, a professor in the Department of Earth Systems Science at the University of California at Irvine, presented evidence that aviation's estimated contribution to greenhouse gas emissions is about 3 percent, which is comparable to the role of California or European nations such as France and Germany. He also noted that because of the complexity of aviation's interaction with the atmosphere, there will be several opportunities for the industry to lessen impacts on the climate.  Joyce Penner, a faculty member of the University of Michigan's Atmospheric, Oceanic, and Space Sciences Department, spoke about the uncertainty of some of the data presented in the IPCC report, especially those regarding cirrus clouds.  She noted that because of lack of funding, IPCC research on these topics has, unfortunately, halted.  When questioned about alternative fuel engines, Stephen Henderson, from the Boeing Commercial Airline Group and Project Director of IPCCs Airline Industry Analysis, stated that current engines could run on fuels other than gasoline, but that currently it is not economically practical to use them.  (10/26/99)

CO2 and Temperature over the Last 420,000 Years: Present and Projected Climate Changes in

On September 30th, French scientists Dr. Jean Jouzel of the Laboratoire des Sciences du Climat et de l'Environnement and Dr. Dominique Raynaud of the Laboratoire de Glaciologie et Geophysique de l'Environnement spoke as part of the U.S. Global Change Research Program (USGCRP) Seminar Series on Capitol Hill.  The lecture, titled "CO2 and Temperature over the Last 420,000 Years:  Present and Projected Climate Changes in Perspective," gave an overview of their article in the June issue of Nature concerning recently collected data from the Vostok ice core in Antarctica.  Jouzel and Raynaud's main points included:  1)  The present-day CO2 and methane levels are unprecedented over the last 400,000 years, 2)  In the past, greenhouse gases (mainly CO2) served as a positive feedback mechanism, strongly amplifying glacial-interglacial temperature changes that were initiated by Milankovich cycles, 3)  Computer simulations need CO2 forcing to reproduce past climate records.  Vostok is the deepest ice-core every drilled, reaching a depth of 3,623 meters.  The new section of the ice core significantly extends the record of climate properties in the southern hemisphere from records of the last two glacial episodes to data from the last four glacial-interglacial cycles.  Comparison of these data with that taken from the northern hemisphere's Greenland ice cores reinforces the hypothesis that there is a positive correlation between paleo-temperature and atmospheric greenhouse gas concentration.  (9/30/99)

Global Warming Will Not Cause the Seas to Rise

At a Capitol Hill luncheon briefing on September 24, 1999, Fred Singer, president of the Science and Environmental Policy Project (SEPP), gave a lecture titled "Global Warming Will Not Cause the Seas to Rise."  Singer presented his hypothesis that warmer temperatures actually cause the rate of sea-level rising to decrease due to increased evaporation from the oceans and increased precipitation near the ice caps.  Singer's main pieces of evidence were IPCC-published global average temperature data, tropical average sea-surface temperature data, and sea-level data between 1900 and 1970.  Manipulation of this data shows an inverse correlation between sea-level rise and temperature curves, mainly during the warming trend between 1920 and 1940.  Singer has authored several articles and papers, as well as a book titled Hot Talk, Cold Science:  Global Warming's Unfinished Debate, that contest conventional wisdom about increased atmospheric greenhouse gas concentration and its possible effects on the Earth's climate.  (9/24/99)

Please send any comments or requests for information to the AGI Government Affairs Program.

Contributed by AGI/AAPG Geoscience Intern Alison Alcott, 2000 AGI/AIPG Geoscience and Public Policy Interns Nathan Morris and Intern Michael Wagg

Last Updated: July 14, 2000

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