Global Warming Prediction L. David Roper Professor Emeritus of Physics Virginia Polytechnic Inst. & St. Univ. Global Warming and Peak Oil may be the greatest challenges that humans have encountered in the last 10,000 years.

Global Warming Prediction  It is very important to account for fossil- fuels depletion when calculating Global Warming predictions. fossil- fuels depletionfossil- fuels depletion  Otherwise, it might be assumed that more carbon can be put into the atmosphere from burning fossil fuels than physically possible.  Calculating fossil-fuels depletion is not exact, but can be estimated reasonably well.

Fossil Fuels Global Warming  Fit depletion curves to extraction data for coal, crude oil and natural gas using discoveries data and reserves estimates.  Calculate the carbon emitted due to burning fossil fuels and the CO 2 concentration in the atmosphere, accounting for residence time.  Calculate the Earth temperature due to the CO 2 in the atmosphere, including time lag.  Consider triggering of other effects that raise temperature, including temperature feedbacks that increase CO 2 concentration.

Verhulst Function for resources depletion. Verhulst Function: An asymmetric peaked curve. Q  = amount already extracted + amount left to be extracted = total amount to be extracted n ≠ 1 allows asymmetry.

Peak Oil Oil discoveries will not allow higher average extraction. Skewed toward later times.

You can’t extract it if you have not discovered it! The areas under the two curves are the same: ~2x10 12 barrels. Areas under both curves are the same. That is, the amount discovered equals the amount extracted. discoveries extraction

Gas discoveries will not allow higher average extraction. Peak Gas Skewed toward later times.

You can’t extract it if you have not discovered it! The areas under the two curves are the same: ~8x10 15 cu. ft. Areas under both curves are the same. That is, the amount discovered equals the amount extracted. discoveries

Double known coal. Unlikely! Known existent coal (EIA) Peaks between 2060 & 2100

Factors and Assumptions  Coal = 50% carbon, short ton = tonnes  Crude oil = 84% carbon, bbl = tonnes  Natural gas = 76% carbon, tcf = tonnes  CO 2 concentration in ppmv = 0.47 x gigatonnes carbon emitted (may increase with high concentration; i.e., may be nonlinear; see later)  Climate sensitivity = 3°C for doubling CO 2  25% of fossil fuels are used to make useful materials or are lost instead of being burned.  Background year 1700 CO 2 concentration = 280 ppmv

20% left after 250 years 10% left after 2000 years 6% left after 10,000 years

Equation for CO 2 left in nth year for emissions in all previous years.

Coal CO 2 emissions and CO 2 concentration contribution. Shift in ppmv is due to CO 2 residence time.

Crude-oil CO 2 emissions and CO 2 concentration contribution. Shift in ppmv is due to CO 2 residence time.

Natural-Gas CO 2 emissions and CO 2 concentration contribution. Shift in ppmv is due to CO 2 residence time.

Fossil-Fuels CO 2 emissions and CO 2 concentration contribution.

CO 2 concentration due to Fossil-Fuels burning Peaks at about 2110.

CO 2 concentration due to Fossil-Fuels burning + background Below measured data, as it should be.

Non-Fossil-Fuels CO 2 Emissions Assume that non-fossil-fuels CO 2 concentration is proportional to concentration due to burning fossil fuels. Deforestation Soil depletion Cement production Domestic animals

Fit of CO 2 Concentration Data to Fossil-Fuels Emissions Pre-fossil-fuels industrialization NFF=14% of FF

CO 2 concentration due to Fossil-Fuels burning + Non-fossil-fuels sources; latter assumed proportional to fossil-fuels concentration.

CO 2 concentration due to Fossil-Fuels burning + Non-fossil-fuels + background 465 ppmv Carbon-dioxide concentration due to burning fossil fuels with non-fossil fuels emissions, assuming that no Earth states are triggered. It peaks at about 2100 instead of rising into the next century as many assume.

Climate Sensitivity (s) Earth average atmospheric temperature rise due to doubling the carbon-dioxide concentration in the atmosphere. Accounts for fast feedbacks, such as ice melting. The average is about 3 degrees Celsius. It must be applied each year using the carbon- dioxide concentration for that year. C 0 =concentration for reference year (1700).

Climate-Response Function There is a time lag for the atmospheric temperature after carbon emissions. Data errors are large. Fit of two hyperbolic tangents to the data. Due to energy absorbed and released later in mostly the oceans, but also in ice.

Climate-Response Function The climate-sensitivity function is multiplied by a series of two hyperbolic tangents: Temperature lag is due to energy absorbed and released later in mostly the oceans, but also in ice.

1.3 degrees C Close to the current measured value. Although the temperature is not extremely high, it hangs around for a long time. Does not account for fluctuations due to global dimming.

Temperature & CO 2 are mutually reinforcing (positive feedback). 8°C Disaster region! Peak in this calculation. Ice age to current interglacial is about 8 degrees C in Antarctica and about half that in the temperate regions. Why such a high projection?!

Assume carbon sequestration or a coal-burning moratorium. Probably optimistic!

Assume carbon sequestration or a coal-burning moratorium. Coal

CO 2 is somewhat reduced by carbon sequestration or a coal-burning moratorium. 430 ppmv; reduced from 465

Temperature is somewhat reduced by carbon sequestration or a coal-burning moratorium. 1.1 degrees C; reduced from 1.3 Will we have waited too late?!

Double the coal extracted. Coal

CO 2 concentration due to doubled coal extraction 490 ppmv

Temperature is increased due to doubled coal extraction degrees C Instead of 1.3

Temperatures for some of the cases considered Coal Moratorium or Carbon Sequestration Double Coal Assumes that there is no triggering of Earth states.

!Some Nightmares!  Suppose concentration/emissions factor changes with increasing concentration from 0.47 to 0.94 (land and ocean become saturated with CO 2 ).  Suppose permafrosted tundra release of carbon during the next century (example of temperature feedback).  Suppose climate sensitivity changes from 3 to 4 over the next two centuries. (It is known that it changes to 6 over millennia because of slow feedbacks.)

Suppose concentration/emissions factor changes with concentration from 0.47 to 0.94 (doubled). Due to land and oceans being saturated with carbon dioxide. 820 ppmv Assumes hyperbolic-tangent change with 450 ppmv break point and 50 ppmv width. Disaster Region!

Suppose emissions/concentration Factor changes with concentration from 0.47 to 0.94 (doubled). Dangerously high temperatures 2.7 degrees C

Assume permafrosted tundra release of carbon. Total 400 gigatonnes Example of temperature feedback; there are other temperature feedbacks.

CO 2 concentration due to permafrosted tundra release of carbon

Total CO 2 concentration including permafrosted tundra release of carbon Disaster Region! 555 ppmv

Temperature including permafrosted tundra release of carbon. Disaster Region! 1.8 degrees C

Worst case CO2 concentration Most likely fossil-fuels depletion, CO 2 feedback & carbon release in Arctic 1110 ppmv !Calamitous!

Worst case temperature Will cause terrible catastrophes for human life. (See Six Degrees: Our Future on a Hotter Planet by Mark Lynas.)Six Degrees: Our Future on a Hotter Planet 4.5 degrees C for climate sensitivity change to degrees C for climate sensitivity = 3 Approximately the same temperature change between the last glacial maximum and now!

Temperatures for some of the cases considered Coal Moratorium or Carbon Sequestration Double Coal !Could a coal moratorium keep those disastrous Earth states from triggering?!

Fossil Fuels Burning Reduction Reduces temperature below now, which might keep from triggering carbon releases and other temperature- raising feedbacks.

Conclusions  Peaking fossil fuels keeps CO 2 concentration from going extremely high, unless it triggers other effects.  Since temperature rise of about 0.8°C from 18 th century is already causing disastrous events, the continuing increase of another 1°C or more will cause even more disasters and may other Earth changes that will cause a higher temperature.  The peaking of fossil fuels may be as large immediate disaster as is global warming.

World Population Projections Fit of population to available fossil-fuels energy Population without renewable energy Population with renewable energy

Next Major Ice Age with Global Warming Effect Accounting for claim that Earth average temperature changes are about half Antarctica average temperature changes.

This lecture is on the Internet, along with other related lectures:  ingPrediction.ppt ingPrediction.ppt ingPrediction.ppt  (Future Energy)  MIA.ppt (Energy, Global Warming and the Next Major Ice Age) MIA.ppt MIA.ppt