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Vostok Climate Change Data. By C. Kohn, Agricultural Sciences Waterford, WI. Vostok. Source: Michigan State Univ: http://www.globalchange.umich.edu/gctext/Inquiries/Inquiries_by_Unit/Unit_8a.htm.
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Vostok Climate Change Data By C. Kohn, Agricultural Sciences Waterford, WI
Vostok • Source: Michigan State Univ: http://www.globalchange.umich.edu/gctext/Inquiries/Inquiries_by_Unit/Unit_8a.htm • Vostok is a former Soviet Military Base that was converted into an international scientific research station. • As snow is packed into ice by the weight of each year’s snowfall, air is trapped and preserved in air bubbles. • These air bubbles are like small time capsules, preserving air for analysis.
Ice Age & Gas Age as a Function of Depth • This graph shows the relationship between the age of the ice, the age of the gas in the ice bubbles, and the depth of the ice. • As the ice gets deeper, the ice & gas is older. • The straightness of this line also shows that the ice has been largely undisturbed, making it an ideal source of preserved data. Older Why wouldn’t there be any ice data for the present day?
The Factors • The factors we measure in the ice are as follows: • Carbon Dioxide (CO2) – by product of fuel consumption (bodily and transportation); increases atmospheric heat retention. • Methane (CH4) – results from anaerobic digestion, 21x more potent than CO2 at heat retention • Atmospheric Dust – raises/lowers global temperatures • Deuterium (2H) – ‘heavy’ version of Hydrogen; ratios of this isotope in ice indicate global temperatures for a given year.
Carbon Dioxide (CO2) • CO2 is the byproduct of cellular respiration, decomposition, and burning. • When our cells break down sugars and fats for energy, water (H2O) and carbon dioxide (CO2) are created and expelled as we breath out. • CO2 occurs naturally in the environment and is necessary for life on earth. • Plants use this CO2 in photosynthesis to make more sugars, starches, and fiber.
Carbon Dioxide (CO2) • Normally CO2 levels are kept within moderate ranges by natural biological activity. • After CO2 is expelled by living organisms, it is reabsorbed by plants in the process of photosynthesis and converted into sugars and plant tissue. • CO2 levels have risen above natural limits almost solely because of human activity • When we burn fossil fuels, we release CO2 without reabsorbing it. • Every time a fossil fuel is burned, CO2 levels rise higher. • This is a concern because CO2 can absorb energy, like heat.
Carbon Dioxide (CO2) • In a way, CO2 is sort of like the windows on your car. • Normally, the “CO2 window” is open a little so that the car gets warmer, but not too warm. • However, as CO2 levels rise, the effect is similar to closing the windows on a car – less heat is lost and temperatures rise. • It’s not that heat is ‘trapped’. Rather, it’s just not lost as much.
CO2 – Molecular Insulation. • Carbon dioxide consists of one carbon atom with an oxygen atom bonded to each side. • The CO2 molecule can absorb infrared radiation from the sun, and then release it again. • The now-released radiation will be absorbed by yet another greenhouse gas molecule and the cycle continues. • This absorption-emission-absorption cycle serves to keep the heat near the surface, effectively insulating the surface from the cold of space. • This is a good thing…in moderation. • Without CO2, heat would be completelylost to space. Too much can be a problemtoo though. • http://www.ucar.edu/learn/1_3_1.htm
Methane – CH4 • CH4, or methane, is released when living things decompose or are broken down in the absence of oxygen (such as in the stomach of a cow). • In the atmosphere, methane absorbs radiation that would otherwise escape into space, converting it into heat. • Methane is 21 times more powerful at warming than carbon dioxide (CO2) • Once released remains in the atmosphere for 12 years.
Pre-Industrial CO2 & Methane Concentrations. • This graph shows the fluctuation of methane (top) and CO2 (bottom) over the course of the past 150,000 years. • CO2 naturally fluctuated between 200 and 300 ppm (parts per million) prior to the Industrial Revolution. • i.e. the natural maximum of CO2 is 300 ppm. • Methane stayed between 300 and 700 ppb. Older
Pre-Industrial CO2 & Methane Concentrations. • Today’s levels of methane and CO2 are much higher than the ‘natural maximums’ indicated by air trapped in the ice. • CO2 levels for October 2011 are 388.92 ppm • Methane levels are at1800 ppb. • Source: NOAA
Temp Rate of Change • Temp rate of change is how quickly the average temperature changed every 1000 years. • The previous maximum rate of change in average temp was 2.5o C – naturally, the temperature of the earth has never risen by more than ~2.5 degrees per 1000 years. • This large of an increase was followed by an immediate drop of a similar magnitude (the Wisconsin Ice Age). Wisc. Ice Age Older
Heavy Hydrogen • How do we know what the temperature was like 150,000 years ago? • We can calculate temperature by looking at deuterium levels in the trapped air in the ice bubbles. • Deuterium is the ‘heavier’ version of hydrogen. • All atoms have three parts – electrons, protons, and neutrons. • Hydrogen can have no proton (1H) or it can have one proton (2H). Hydrogen with a proton is called deuterium. • The warmer the air, the more deuterium we find in the air (it takes more energy in the atmosphere to keep the heavier hydrogen in the air).
Global Average Surface Temperature • This graph shows the increase in temperatures on the surface of the earth. Average is in red; range of error (95% accuracy) in black. • Graph courtesy of NASA • Since 1900average temphas increasedby 1.4 Co • This is 10x faster than normal. • The 20 warmest years have all occurred since 1981, and the 10 warmest have all occurred in the past 12 years (NOAA.gov)
Temp spikes coincide with GHG spikes. • Spikes in CO2 and methane occur before spikes in temperature, indicating that these gases are responsible for increases in temperature (and not vice versa).
What do we know? • We know that CO2 levels are at least over ~150% higher than the ‘natural’ average, and ~50% higher than the natural maximum high. • We know that methane is 257% higher than its previous natural maximum (and that methane is 21x worse as a greenhouse gas). • We know that this in no way resembles a ‘natural’ cycle – all evidence points to this being a manmade problem. • Rate of increase • Timing of increase
Summary • We know that the average global temperatures have increased as much in one century as they typically would over 1000 years. • We know that temperatures will likely rise 2-5o C more in the next century (and possibly higher still.) • We know that the previous maximum climate rate of change was between +/- 3o C • i.e. we are on par to meet or surpass the maximum rate of change at a pace ten times faster than natural!
Temperature projections to the year 2100. • Figure 1: Temperature projections to the year 2100, based on a range of emission scenarios and global climate models. Scenarios that assume the highest growth in greenhouse gas emissions provide the estimates in the top end of the temperature range. The orange line (“constant CO2”) projects global temperatures with greenhouse gas concentrations stabilized at year 2000 levels. Source: NASA Earth Observatory, based on IPCC Fourth Assessment Report (2007)
Presentation to Forum 2002, St Anne’s College, Oxford, 15 July 2002 by Sir John Houghton
But what about the sun? • The sun’s energy output has actuallydecreased in recentyears while tempson earth have increased. • i.e. We know this is not from the sun!
Summary • We know that the earth naturally warms and cools. • However, we also know that the earth does not naturally warm and cool at this fast of a pace. • While we have had ice ages and warmer climates in the past, these changes took much, much longer to occur. • Natural mechanisms for species adaptations cannot change at the same rate at which the planet is changing. • Species will go extinct at an increasingly faster rate if their habitats change too quickly!
Climate Change Predictions for the Midwest (2009) • By the end of this century, the Midwest could face more simmering Texas-style heat in summer, more Seattle-like downpours in other seasons and levels of some Great Lakes that are as much as 2 feet lower. • Those are among the worst-case scenarios in a new study on climate change compiled by 13 federal agencies. Past reports have targeted the global effects of rising global-warming gases, but the latest report covers findings for the United States. • The 200-page report by the Global Climate Research Program synthesized a number of recent studies, many of which have already been made public. • The study said average temperatures across the United States have risen by 2 degrees in the past five decades and could rise another 4 to 11 degrees by 2100. • If the nation cuts global-warming gas emissions, the temperature increase will be at the low end; if not, it will be at the high end. Source: Michigan State University Libraries