Download
1 / 22
220 likes | 239 Views
This comprehensive guide delves into carbon storage strategies, the long lag time in carbon retention, and the physics of the climate change problem. It explores the concerns surrounding global carbon emissions, carbon accounting, and the urgent need for carbon intensity reduction. The text also presents energy efficiency, new fuel sources, and CCS strategies, emphasizing the importance of international efforts to combat climate change.
E N D
Carbon Storage Mitigating Climate Change? Will this work? Is it too late?
Lag Time Issue • Is really quite serious • We don’t even know yet of the climate system is responding to increased CO2 • Other factors (water vapor feedback loop, aerosol suppression, increased clouds) may be at work • If the lag time (some times called the warming pipeline) is large then stabilization targets may be coming too late
The Physics of the Problem • CO2 long atmospheric lifetime • Ocean (water) takes a long time to heat up and cool off ocean SST is primary driver of global climate change. • Estimates suggest warming pipeline is 0.5 – 1 degree C (and there is nothing we can do about this)
Probability and Concerns • A recent, thorough analysis has yielded this thoroughly discouraging result:
Complications • Aerosols/global dimming may well be masking the warming signal this is an area of much current research • Feedback from clouds looks likely to be positive rather than negative in the most recent grid models that actually contain clouds • This means the 2 degree C stabilization target has already been exceeded
Carbon Accounting I • 1 ppm CO2 = 2.1 GigaTons of C • Averaged over last 10 years net increase has been 1.8 ppm or 3.8 GTC annually • Sources = 7.7 (fossil) + 1.4 (deforest) = 9.1 • Sinks = 3.0 (forests) + 2.3 = 5.3 • 9.1 -5.3 = 3.8
Carbon Accounting II • Current rate (2008-2010) = 2.5 ppm so we are rapidly exceeding the Sinks. • Make simple model – Assume sinks remain constant at 5.3 GTC removal. • Can then roughly figure out stabilization levels for emission targets. • Very likely nothing can be done about the 1.4 GTC from deforestation so concentrate on the fossil fuel issue
Carbon Accounting III • Cut emissions by 25% = 5.7 • Emissions still rise by (5.7+1.4 - 5.3)/2.1 = 0.85 ppm per year still that’s much less than the current rate of 2.5 ppm! • Cut emissions by 50% = (3.85+1.4 - 5.3) =5.25 and now your in equilibrium • Cut emissions by 75% =(1.9+1.4 -5.3) and you get only 1 ppm reduction per year • Do this today at you get to 350 ppm in 40 years.
Continue BAU for 10 more years-Carbon Intensity @1% per year • Reach 430 ppm of CO2 • Net annual C increase is now 5.8 GTC • Fossil source function is now 8.7 GTC • 50% reduction then = (4.35+1.4-5.3) = 0.45/2.1 = 0.2 ppm increase • 75% reduction then = (2.18+1.4-5.3)=-0.8 ppm per year so now it takes 100 years to reach 350 ppm! This should set policy framework!
Avoiding The 500 PPM Level • Our current annual emission is 7 GTC! BAU trajectory is 500 ppm by 2050 or adding 175 GT over next 50 years above current baseline. Must therefore suppress 3.5 GT year (which is 50% of the current rate) • Look for somewhat equal contributions in all areas (e.g. storage, production, fuel, etc) Wedge steps to get there by 2055 • Each Wedge requires a large scale, multi-national effort! • Wedges correspond to worldwide emissions – each country’s contribution varies; US will have to reduce or sequester about 80% of its current carbon emission to play fair
Energy Efficiency and Conversion Strategies • Increase fuel economy for 2 billion cars from 30 to 60 mpg • or, decrease annual miles for 2 billion 30 mpg cars from 10,000 to 5000 • Efficient buildings: cut carbon emissions in buildings by 25% • Increase coal fired electricity efficiency from 40% to 60% using advanced high temperature materials
New Fuel Sources Strategies • Replace 1400 GW of 50% efficient coal fired plants with natural gas fired plants • Increase ethanol production by a factor of 100 relative to current US production utilizing 1/6 of world available cropland • Add 4 million 1 MW peak windmills (100 times current world capacity) for Hydrogen production for fuel cells
CCS Strategies • Capture at baseload power plant (at 800 GW Coal or 1600 GW of Natural Gas) • Capture at steam-reforming Hydrogen production plants at levels of 250 Mt/year for gas and 500 Mt/year H-production by coal • Capture at coal-liquid plants crucial; future facilities could produce 30 million barrels a day
Alternative Energy Strategies @ 2TW Electricity Production • Need more due to lower capacity factor of Alternatives (30-40%) compared to Fossil or Nuke plants (90%). • Substitute wind power for Coal power at the scale of building 400,000 5 MW turbines on land or offshore • Substitute PV power for Coal power at the level of 2000 GW North African Desert
Wedge Approach – 1GTC/yrreduction by 2054 • One Wedge achieved by US if it reduces its carbon intensity 2.1% per year for next 50 years • 2 billion cars have large lever arm on the wedge • In 2000, Coal power plants operated at 32% efficiency and produced ¼ of all carbon emissions (1.7 GTC) a wedge is achieved at 60% efficiency
Wedge Approach Continued • One wedge achieved by displacing 1400 GW of coal with gas by 2054. Requires China/Russia agreement on Natural Gas. • Substitute 700 GW of Nuclear fission for Coal would achieve a wedge requires restoration of public confidence in safety and waste disposal • Wedge achieved by implementation of any 2 TW AE scheme for electricity production • 34 million gallons per day of ethanol production achieves a wedge (this is 60 times larger than current world production rate!)
