What is Global Warming?

what is global warming
Tom Morris
Division of Natural Sciences
Fullerton College

Global Warming Teach-In
January 31, 2008

A Short Description of Global Warming

Scientists have observed that the planet's average temperature has increased in the last 100 years -- Global Warming.

global temperatures from 1880 to 2006

CO₂ also has increased in the last 150 years.

global CO2 trend

What Causes Global Warming?

Perhaps humans are to blame.

Most climate scientists today suspect that the main cause of global warming is the increased release of CO₂ from fossil fuel burning -- enhancing the planet's greenhouse effect.

the greenhouse effect

Perhaps nature is to blame.

Others hold that the recent warming is entirely the result of natural processes, like a warming sun.

Potential Consequences of Global Warming

	Changing climate patterns: Drought Geographic shifting of food production regions Starvation Mass human migrations Political and social conflict

	More powerful hurricanes, typhoons and cyclones: Caused by warmer ocean waters

	Rising sea levels: Caused by melting of land-based ice caps If Greenland melts, rise of about 3 meters (left)

	Range expansion of disease-carrying insects: Malaria Dengue fever

	Special challenges to wildlife Migration clocks between dependent species may become unsynchronized. Polar bears threatened with drowning Climate-adjusting migrations blocked by human development

	Whether natural or human-caused, global warming may result in substantial and unpredictable change. It will be expensive for human civilization to adjust to the new environmental regime.

At issue is the notion of cost. Will global warming produce change that will be expensive for us to adjust to? Or, if humans are not causing global warming, why should we incur costs to prevent it?

Skeptics and Deniers

Skepticism is encouraged in all scientific efforts. But such skepticism is only useful if it is driven by a genuine desire to understand.

Sometimes skepticism is used as a deceptive device to spread doubt. Unwelcome scientific findings tend to attract such skepticism -- which is not helpful.

	Skeptics say, "Maybe it's the sun..." Current debate: How to best interpret satellite data: total solar irradiance (TSI) vs. Physikalisch- Meteorologisches Observatorium (PMOD) Trending position: Recent warming cannot be attributed to sun alone.

	Skeptics say, "Climate naturally fluctuates..." Current debate: dynamic relationship between CO₂ and global temperature. Trending position: Natural increases in CO₂ contributed significantly to past warm periods.

	Skeptics say, "The "Hockey Stick" is wrong..." Skeptics' claim : Mann's hockey stick representation of recent global temperature suffers from flawed statistical methods -- and is wrong. Trending position: Revised analyses produce essentially the same hockey stick shape.

	Skeptics say, "The models are wrong..." Skeptics' claim : Models have weaknesses. Results are artificial because modelers tweak their models to fit the known past. Trending position: Models continue to improve in scope, sensitivity and reliability. Many parameters are entirely empirical and are best informed by past-fitting.

	Skeptics say, " Actually, 1934 was the hottest year on record..." Skeptics' claim: Previous interpretations of USA data showed 1934 and 1998 having about the same mean annual temperatures. Corrections placed 1934 as warmest in US history. Trending position: This change has an extremely small influence on previously reported global mean annual temperatures.

How did this Story get Started?

	(circa 1904) Norwegian physicist, Vilhelm Bjerknes, created a set of seven "primitive" equations in an attempt to predict the weather.
	In 1922, British mathematician, Lewis Fry Richardson modeled the atmosphere as gridded cells. Used Bjerknes's equations to compute the weather of an 8-hour period -- it took him six weeks of pencil and paper work.
	In 1946, Hungarian-born American mathematician, Jon Von Neumann, promoted the idea that computers should be used for weather prediction.
	In 1949, American meteorologist, Jule Charney, produced the first computer-generated regional weather predictions. Calculation time for a 24-hour period was... about 24 hours.
	In 1955, Princeton scientist, Norman Phillips modeled weather based on global circulation... the first General Circulation Model (GCM).
	In 1960, Scripps scientist, Charles David Keeling reported steady increases in CO₂ levels over Antarctica.
	In 1965, US Weather Bureau scientists, Joseph Smagorinsky and Syukuro Manabe developed the first spherical general circulation model. This model represented the atmosphere as nine nested spherical shells.
	In 1967, Syukuro Manabe inserted Keeling's observations of rising CO2 levels into his lab's general circulation model -- The result was the first modeled prediction that such increases would produce global warming.

Predicting Global Climate Demands Hard Work

	Characterize the current global climate system.

	Understand the physics of climate components.

	Develop abstract models of climate operations (General Circulation Models).

	Write computer code to numerically represent the general circulation model operations.

	Design and build super computers to run general circulation model simulations.

	Test the model's reliability by testing if can predict past climates.

Scientists Train for Years to get the Skills

	Mathematics Calculus Trigonometry Differential equations Linear algebra Statistics

	Physics Thermodynamics Fluid dynamics

	Chemistry Organic chemistry Biochemistry Physical chemistry

	Earth science Geology Oceanography Meteorology Biogeochemistry

	Computer science Algorithms and data structures Computational physics FORTRAN

Present Day Reports

	Goddard Institute for Space Studies Global Temperature Trends: 2007 Summation The year 2007 tied for second warmest in the period of instrumental data, behind the record warmth of 2005, in the Goddard Institute for Space Studies (GISS) analysis. 2007 tied 1998, which had leapt a remarkable 0.2°C above the prior record with the help of the "El Niño of the century". The unusual warmth in 2007 is noteworthy because it occurs at a time when solar irradiance is at a minimum and the equatorial Pacific Ocean is in the cool phase of its natural El Niño-La Niña cycle.

	The Hadley Center, Climate Research Unit, University of East Anglia, UK Global Temperature Record The time series shows the combined global land and marine surface temperature record from 1850 to 2007. The year 2007 was eighth warmest on record, exceeded by 1998, 2005, 2003, 2002, 2004, 2006 and 2001.

	NOAA Earth System Research Laboratory Trends in Atmospheric Carbon Dioxide - Mauna Loa

	Goddard Space Flight Center Minimum Sea Ice Comparison: 2005, 2007 The 2007 Arctic summer sea ice reached the lowest extent of perennial ice cover on record - nearly 25% less than the previous low set in 2005. The area of the perennial ice has been steadily decreasing since the satellite record began in 1979, at a rate of about 10% per decade. But the 2007 minimum, reached on September 14, is far below the previous record made in 2005 and is about 38% lower than the climatological average. Such a dramatic loss has implications for ecology, climate and industry.

	NASA and the International Polar Year Antarctic Ice Loss Speeds Up, Nearly Matches Greenland Loss Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists.

	Tata Motors The making of the Nano The launch of the People's Car by Tata Motors is a defining moment in the history of India's automotive industry. For Tata Motors, the car — christened the Nano, because it is a small car with high technology...

What is Global Warming?

	To oil, gas and coal industries... Financial impacts: Reductions in future sales. Devaluation of extensive capital investments in facilities and infrastructure. Added costs for compliance to future environmental regulations.

	To automobile industries... Financial impacts: Added costs to redesign and engineer new power plants. Established market positions vulnerable as consumer choices shift. Devaluation of extensive capital investments in production facilities.

	To electricity providers... Financial impacts: Added costs to comply with new CO2 emissions limitations. Devaluation of extensive capital investments in power plants and supporting facilities. Added costs to redesign, engineer, build and deliver energy under a low/no-carbon regime. Enormous costs associated with design / construction of new generation of nuclear power stations.(?)

	To water suppliers... Political and operational impacts: Adjusting allocation policies to changing precipitation patterns. Adjusting water storage operations to the "longer, hotter summer" scenario.

	To farming and livestock industries Financial and operational impacts: Suffering lost crop yields due to increased drought, drier soils, introduction of new pests, hotter temperatures, irrigation water shortages. Devaluation of existing capital investment unsuited to new growing regime. Added cost of recapitalizing farm for new climate. Difficulty acquiring credit and insurance in regions experiencing changing climate.

	To public health providers Operational impacts: Adjusting to diseases migrating from tropical to sub-tropical latitudes (malaria, Dengue fever).

	To banks and insurance companies... Financial impacts: The biggest concern is "unpredictability". Reduced confidence in assessing risk in credit and insurance markets. Loss of future profits as a result of: Lending or underwriting losses due to unpredictable climate change. Departure from previously lucrative markets now made unpredictable by changing climate.

	To wildlife... Redistributions and extinctions: Plants, animals, fungi, algae and microbes will tend to reorganize themselves as their environment changes. Migrations will be hampered by human land uses. Extinctions will occur if all individuals of a species fail to make the shift.

	To residents of the Maldives Islands... Flooding from sea level rise: This island country has an average elevation of 1.8 meters above sea level. Modest melting of Greenland and Antarctic ice caps will flood these islands. Higher storm surges from more intense storms poses flooding risks.

	To people around the world like you and me... We will be faced with new choices and new opportunities: The world is rapidly changing -- with or without global warming. Get ready for it. Prepare yourself to be flexible and adaptable. Stay in college. Focus on "skills" not grades. Reevaluate the necessity for "excess" in your life. Stay informed. Make informed and ethical choices that are consitent with environmental realities. Trust in the ingenuity and resourcefulness of humankind.

	Conclusion
Currently, global warming does not represent "catastrophic" change to most of the world. But I recommend that you pay attention to this important issue as it continues to develop. Scientists and policymakers will continue to work out the details to global warming over the next decade or three. Aside from global warming, there are other important global environmental changes happening right now brought about by: Rapid human population growth Rapid industrialization in the developing world Rapid consumption of petroleum reserves Rapid development of wild lands As more and more billions of people demand a greater personal share of the world, our choices and opportunities will be transformed. There will be many new, inviting opportunities. There will be losses. Get yourself ready to do your part to move forward responsibly and ethically.

Conclusion

Currently, global warming does not represent "catastrophic" change to most of the world.
But I recommend that you pay attention to this important issue as it continues to develop.
Scientists and policymakers will continue to work out the details to global warming over the next decade or three.
Aside from global warming, there are other important global environmental changes happening right now brought about by:
- Rapid human population growth
- Rapid industrialization in the developing world
- Rapid consumption of petroleum reserves
- Rapid development of wild lands
As more and more billions of people demand a greater personal share of the world, our choices and opportunities will be transformed.
There will be many new, inviting opportunities.
There will be losses.
Get yourself ready to do your part to move forward responsibly and ethically.