Storm Warnings: Climate Change and Extreme Weather

Book Review: Storm Warnings: Climate Change and Extreme Weather - from the editors of Scientific American (Dec. 2012)

Here is a series of Scientific American articles on climate topics. There are twenty five papers on a variety of topics including superstorms, oceans, glaciers, global warming, climate politics, and solutions. The first series of papers is about Hurricane Sandy and other extreme weather events. Then the possible and probable causes and mechanisms are examined. Finally solutions are explored. This was cheap on kindle, about 3 bucks.

Hurricane Sandy wrought significant damage and really tended to focus attention on extreme weather events that could be attributed to climate change caused by increased greenhouse gases caused mostly by burning of fossil fuels. The first paper by Fred Guterl, The Future According to Sandy (Oct 2012), examines planning for extreme weather events and long-range climate dangers such as sea level rise. Post-Sandy New York City, the lowlands of Holland, and even London are potential problem areas. New Orleans has already had a taste of what storm surges can do.

The next article by Mark Fischetti, Did Climate Change Cause Hurricane Sandy? (Oct 2012), examines whether climate change caused Hurricane Sandy. Part of the mechanism of this superstorm involved a North Atlantic Oscillation (NAO) which refers to the state of atmospheric pressure over the North Atlantic. Recent research by Charles Greene at Cornell University has shown that summer melting of Arctic sea ice affects the NAO – makes it more likely to be negative during autumn and winter. This may cause the Jet Stream to move across North America in a big wavy pattern – causing it to dip further southward as it did during Hurricane Sandy. Other climate change affects on storms include warmer oceans which provide more energy for storms. A warmer atmosphere is also able to hold more moisture so that more is available for storm events. Prominent climatologist James Hansen points out that heat waves and droughts are also caused by climate change as the real data shows – not just climate models. Warmer oceans mean there is a greater likelihood for stronger hurricanes. Even Munich Re, one of the largest reinsurance firms in the world, is considering climate change into its models and notes that damage data over time shows that it has significant costs.

An article by David Biello, The Science of Superstorm Sandy’s Crippling Storm Surge (Nov 2012), examines storm surges – particularly the one from Superstorm Sandy. The storm did over $20 billion in damage. It would have been worse if the storm surge coincided with high tide. The damage from storm surges is dependent on wind speed, storm size, storm trajectory, wave action, and coastal geography that can funnel water inland. Much of Sandy’s storm surge power had to do with its massive size. Flood walls can protect against storm surges but they can also inadvertently keep water in that breaches the wall as happened in Galveston during Hurricane Ike in 2008. Forests, wetlands, and barrier islands also protect but concave shorelines (such as around NYC) can have a funneling effect and bring in more water. Protection against storm surges also has to take into account overall sea level rise that continues as glaciers melt. All coastal cities need to prepare for the slow rise of sea level and the occasional flooding of storm surges.

Next is an article by Mark Fischetti – Northern Hemisphere Could Be In For Extreme Winters. This turned out to be true last winter although the winter of 2011-2012 was the warmest in U.S. history. Winter severity may be related to summer melting of arctic sea ice. More sea ice melting means more sea exposed which absorbs more heat which melts more ice = a positive feedback loop. In autumn the heat is released into the atmosphere. This in turn lessens the difference between the Arctic Oscillation and the North Atlantic Oscillation which then affects jet stream behavior in winter. The more melting of arctic sea ice the more extreme bending in the jet stream is the rule of thumb. The bottom line is that normal winters will be less likely and more likely will be warmer or colder than normal.

Next is – Extreme Weather is a Product of Climate Change – by John Carey. Those who have researched and tracked extreme weather events the longest have noted an increase in them. More record-breaking weather events have come about in recent times than in the past. While it is hard to directly attribute individual weather events to climate change, there are statistics that show an increase of them through time and the more there are and the more powerful they are, the more they cost to fix. A related article also by John Carey is – Global Warming and the Science of Extreme Weather. One very possible driver of more extreme weather is that a warmer atmospheric temperature means the atmosphere can hold more moisture so more can be available for storm events. It may be that global precipitation actually becomes less and local precipitation much more intense as some models suggest. Add warmer ocean temps and there is the possibility of stronger hurricanes. A warmer atmosphere means changes in atmospheric circulation which could help explain superstorms, tornadoes, droughts, and subsequent wildfires. Weather events with evidence of influence from global warming include the European heat wave of 2003 and 2005’s Hurricane Katrina, say scientists at NOAA and NCAR. It was calculated that global warming could be responsible for an inch or more, possibly much more, of the rain from Katrina, seemingly not much, but enough to make matters worse. There is some controversy about how much climate change has affected certain weather events but climate scientists agree overwhelmingly that there is some influence. A third article by John Carey in this section is – Predicting and Coping with the Effects of Climate Change. Some U.S. politicians still think climate change is a hoax while others like the Russians are beginning to believe it because they see the effects of it at home. Predictions are simply for more extreme weather events including floods, drought, wildfires, tornadoes, hurricanes, derechos, dust storms and typhoons. Some predict dry conditions in the plains like the seven year “dust bowl” of the 1930’s. Water shortages in the American southwest may increase. Some cities are preparing by increasing their storm drainage capacity. Farmers are planting earlier in a warming climate, adding tile drainage to fields subject to flooding, planting more seed to utilize the extra moisture, and utilizing heavier equipment to plant and harvest faster to take advantage of climate “windows.” Flood insurance requirements have increased. Wetland restoration also helps mitigate floods. Each extreme weather event is a wake-up call to preventative action but such action is often abandoned in times between such weather events.

Next we move to Glaciers and David Biello’s 2006 article – Greeenland’s Glaciers Are Going , Going… The Greenland ice sheet has been melting even beyond the climate change predicted models. Here it was noted that melting was accelerating to the point where there was 20% more loss than gain with winter snowfall. Different types of measurements confirm this. Bottom line is that the Greenland ice sheet is losing mass significantly faster than predicted and this is a cause for concern.

Next is – Is Soot the Culprit Behind Melting Himalayan Glaciers? – by David Castelvecchi (Dec. 2009). Apparently the Himalayan mountain region is warming about three times faster than the mean and mountain glaciers are melting. A cloud of soot, or black carbon, covers much of India, produced in part by millions of small wood cook stoves. Forest fires and power stations are also major contributors of soot. The particles absorb sunlight and contribute to warming the atmosphere. Soot also falls to the ground, including on snow, where it can darken it and cause the snow to absorb more sunlight. This can speed up glacier melting. Models suggest that the soot in the Himalayas can cause a 24% increase in snow melt. Heating of the atmosphere over India has been confirmed. Soot is implicated as well in increasing the melt of the polar ice caps. The good news is that soot does not linger long in the atmosphere – usually just a few weeks – so mitigation efforts can see quick results. One thing being done is development of less polluting cook stoves – wood ones that produce less soot, natural gas ones that make even less, and solar ones that make none. Overall, soot is a factor but greenhouse gases such as CO2 are far greater direct causes.

Next is – Witness to an Antarctic Meltdown – by Douglas Fox (July 2012). The Larsen A ice shelf in Antarctica collapsed in 1995. When an ice shelf breaks up the glaciers behind it will fall into the sea eventually. How quickly this will happen is not easy to predict. It is hard to predict ice shelf collapse too. This makes for some serious uncertainty in predicting sea level rise. If glacier melt is accelerated then so too will be sea level rise. So far it seems that glacier melt has been underestimated. In summer of 2002 the Larsen B ice shelf “disintegrated into hundreds of shards.” After this about 150 cubic kilometers of glaciers melted into the sea causing the tectonic uplift of the underlying earth’s crust to triple. Apparently Larsen B broke up into smaller pieces than expected. Scientists have put equipment in place to test theories of how ice shelves will collapse in the future. They can also estimate when the same ice shelves collapsed in the past through geological means. Some areas such as those around Larsen A have collapsed previously about 4000 yrs ago but the area around Larsen B had been in place for a minimum of 11000 yrs and possibly tens of thousands of years longer. Increased wind speeds scouring more snow off the glaciers to then melt into the sea could be another melt acceleration factor. Some of these glaciologists think that the IPCC sea level rise estimates for 2100 could be underestimated by half or three times, meaning we could see over a meter of sea level rise by then.  

Next is David Biello again with – Deny This: Himalayan Glaciers Really Are Melting (July 2012). In 2010 some climate change contrarians denied that Himalayan glaciers were melting at all but now we have satellite data that shows melting, retreating, mass loss, and shrinking. Higher average temperatures and changes in precipitation (also possibly from climate change) are the culprits. According to the author it is another in a long line of refutations of the contrarians.

Now we come to oceans and the first article is: Threatening Ocean Life from the Inside Out by Marah J. Hardt and Carl Safina (Aug 2010). Too much CO2 in the ocean causes acidification as it reacts with seawater to form carbonic acid. This can cause difficulty for animals to build their shells and disrupt some bodily and reproductive functions. Creatures must expend more energy balancing their internal pH. Comparable changes in ocean acidity in the past were connected to widespread loss of sea life. Sea life can adapt to changes in acidity by making more buffer molecules but such mutations require a much longer time scale than that on which the current man-made acidification is occurring. It is likely that some species will adapt and others will perish. Absorption rate of CO2 will slow as acidification increases causing the ocean to be less of a carbon sink.

The authors recommend establishing marine species protective areas to prevent overexploitation through fishing and to devote more study to ocean acidification.

Next is: Coral Reefs at Risk – by John R. Platt (Aug 2010).  Rising surface water temps, acidification, and human interference are putting many reefs at risk. Higher temps cause bleaching and death of reefs. Those around Indonesia are severely damaged. Less reefs means less habitat for fish and less fish for humans. Acidification leads to problems with reefs building their skeletons. Ships can also damage reefs as well as oil spills. Illegal trade of coral can also damage reefs. Scientists are trying to understand why some coral bleach and die and others don’t. So far it seems to be dependent on energy for immune response of different species of coral.

Now we come to Greenhouse Gases and Global Warming with James Hansen’s famed paper – Diffusing the global Warming Time Bomb (March 2004). This is perhaps one of the most important papers written on Global Warming. It is a “big picture” view, a detailed yet not too technical explanation of the concepts involved, and has suggestions to resolve what Hansen describes as a most dire crisis. He is perhaps more alarmist than other scientists but much of his science is indisputable. Here we learn about climate history and how it has been determined, mainly from ice cores which reach back 400,000 years. We learn about climate forcings, feedbacks, solar insolation, the planetary energy imbalance, and climate sensitivity:

“Objective analysis of global warming requires quantitative knowledge of three issues: the sensitivity of the climate system to forcings, the forcings that humans are introducing, and the time required for climate to respond.”

Hansen thinks the planetary energy imbalance is between 0.5 and 1 watt per square meter which means that the solar radiation being absorbed by the earth is greater by that much than is being emitted as heat back into space. Most of the energy imbalance has been heat going into the oceans. A big uncertainty is how fast ice sheets will respond to global warming. Hansen includes several useful charts, graphs, and diagrams in this article. Hansen’s predictions are more dire than those of the IPCC. One variable that has uncertainty (but is confined within a known range) is the effects of aerosols, small particles in the air that may mitigate warming by reflecting sunlight. As well as reducing CO2, we can reduce methane – efforts are progressing to reduce methane loss from its two main human sources: oil and gas operations and livestock and other agriculture. Other sources are landfills and sewage treatment plants. Reduction of black carbon, or soot, is another opportunity. Captured methane could be used for fuel and captured soot could save lives and improve health so there are other upsides.

Next is: Beyond the Tipping Point by Michael D. Lemonick (Sept 2008). This paper compares the standard climate change view of the IPCC and others with the more alarming view put out by James Hansen and his colleagues. The standard view suggests that global warming will gradually increase as atmospheric concentrations of CO2 increase and that it will accelerate when CO2 concentration hits about 560 ppm. Hansen argues that the critical threshold may be as low as 350 ppm. Levels now are just above 400 ppm and increasing about 2ppm per year on avg. Hansen calls for elimination of coal burning power plants by 2030. Hansen’s model incorporates climate feedbacks that operate on short time scales such as water vapor, clouds, and sea ice. Loss of sea ice and snow cover of glaciers can be a major feedback as the newly darker surfaces will absorb solar radiation rather than reflect it. Hansen thinks letting CO2 concentrations get to 450 ppm could be catastrophic. Other positive feedbacks – changes in vegetation, atmospheric and ocean chemistry, and accelerated release of methane from rotting biomass following melting permafrost – have the potential to seriously accelerate global warming. Gavin Schmidt, another climate scientist at NASA’s Goddard Institute, is less alarmist than Hansen and notes that the feedback mechanisms suggested by the ancient ice record are not that well understood. Schmidt, Princeton’s Michael Oppenheimer, and Stanford’s Stephen H. Schneider acknowledge the shrewdness of Hansen but think that he is being too specific about absolute numbers for tipping points. Abandoning coal power without CO2 capture and sequestration, massive reforestation efforts, and utilization of bio-char for agriculture are some suggested solutions. Bio-char is stable and increases soil fertility so it can sequester carbon and help agriculture. Replacing slash-and-burn agriculture with slash-and-char could reduce CO2 about 8ppm in 50 years – not a massive amount but significant.

Next we have Making Carbon Markets Work by David C. Victor and Danny Cullenward (Dec 2007). Carbon markets are a regulatory method of reducing emissions. Cap-and-trade works by putting a cap on carbon and trading allowances for the right to pollute. Alternatives are a carbon tax or a fee and dividend structure. Cap-and-trade has worked for SO2 and somewhat for CFCs. The early form of European cap-and-trade was wrought with problems due to allowance distribution so that it was unfair in some respects. German coal companies profited as did other companies in Spain, the U.K., and the Netherlands. These companies charged a carbon fee to their customers that in reality they never had to pay due to the allowance distributions, so the European people ended up paying them! That has changed in more recent times. Opponents fear carbon regulation will give unfair advantages to developing nations who so far have not been subject to any regulation. This includes the U.S. although that has begun to change with state and regional carbon markets in place that seem to be working. The new federally mandated rules on power plant emissions are another form. The bottom line is that pollution and greenhouse gas emissions have potential costs to future generations and if we have to pay to pollute there will be more effort put forth for emissions reduction, efficiency, demand response (conserving during high demand times), technological innovation, and clean energy. Trading carbon allows companies to cut pollution by the most inexpensive method they can find, perhaps by funding emissions reductions in other countries that would be cheaper to implement than reducing their own emissions. The World Bank estimates that carbon trading in 2006 was worth $30 billion. The cost of emissions cuts controls pricing. If the U.S. ever creates a carbon market and China and India follow, this would set the stage for a truly global carbon market. The main point is setting carbon caps. Awarding allowances is in essence awarding property rights where none existed before. The problem is that politically connected companies often get preferential treatment as happened in Europe and could happen here. Auctioning permits to the highest bidders would eliminate this problem but coal companies and other high emitters would resist and threaten to raise rates for consumers. Another problem is identifying baseline emissions values. One chemical, HFC-23, has 12,000 times the greenhouse effect as CO2. All industrialized countries remove this product with fairly inexpensive equipment. Some developing countries have manipulated the market by gathering more carbon credits since releasing this chemical keeps their baseline emissions higher, thus making about 100 times the money equivalent in carbon markets. This is shameful and ridiculous and hopefully has been amended since then. A better method for that chemical would simply be to remove it from the market and require the companies to pay directly to remove it. The authors here recommend a five-step plan: 1) establish a mandatory emissions tax policy. This would eliminate any inequities associated with trading. 2) if a cap-and-trade system is adopted there should be a “safety valve” whereby a ceiling on credit prices is declared so that pricing will be predictable. While price stability is desirable, others disagree since this makes the trading scheme more of a tax. 3) industrialized countries should develop smarter strategies for engaging emerging markets. This means helping developing countries reduce their emissions. Emissions reduction should be a key, vital, and valuable part of any energy producing or utility company and emissions reduction techniques should be passed on to developing nations. 4) Energy efficiency should be mandated with more than price signals (as in a carbon market) but with specific mandates for products and processes. 5) Governments should do more to encourage adoption of new technology such as carbon capture and sequestration at power plants. A high enough carbon tax would do it. Otherwise there is no incentive unless it is mandated by the government.

The next section is on Debate. First article is: Climate Heretic: Judith Curry Turns on her Colleagues by Michael D. Lemonick (Oct 2010). Judith Curry heads the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. She has recently entered into dialogues with climate skeptics which has infuriated some of her colleagues. She believes that this is a good thing and prevents over-indulgence in “group think” and dogmatized climate knowledge. I tend to agree. She has strong criticism for the IPCC, saying it needs reform due to “corruption.”  The question is whether she is a peacemaker or a dupe. The climate debate is important and Curry says she wants to engage with the more plausible skeptics as they are the ones with the most real influence on the doubting public. As a reviewer of IPCC Third Assessment Report she says she found ignorance of certain processes among some scientists that shed some doubt on their findings so that she felt their confidence was overstated. She does not doubt the validity of climate science as some climate skeptic blogs seem to indicate but she does think the IPCC has become biased to some extent. Investigations of Climategate and conflict of interest of IPCC chairman Rajendra Pachauri revealed absolutely no fraudulent science. There is uncertainty in the calculations so it is possible that climate change is not as dire as predicted in the models. IPCC tends to downplay uncertainty – perhaps too much, while climate skeptics exploit any mention of uncertainty. Other climate scientists say the IPCC has been upfront about uncertainties. The late Stephen Schneieder, Jim Hansen, and many others note that even though there are uncertainties, they tend to fall within a known range. Schneider and many other climate scientists have called Curry’s charges misleading and charge her with sloppy thinking. The IPCC has been charged with poor communication to policy makers about the uncertainties. Both Curry and the IPCC agree that the public should know that uncertainty is not the same as ignorance. It should also be noted that uncertainty goes both ways. It could be better or worse. Some scientists worry that Curry and others like her have the ability to damage a consensus. But is she being criticized for talking to outsiders, for not playing by the rules of an understood bias? The author of this paper concludes that Curry is both a peacemaker and a dupe as well as an example of the deeply political nature of the climate debate.

Next is: Seven Answers to Climate Contrarian Nonsense by John Rennie (Nov 2009).  The author here gives what he calls “bad arguments” of climate skeptics with brief rebuttals. Claim 1) CO2 is only a trace gas and humans only create a portion of that so gases like water vapor affect the climate more. CO2 has been proven to be very significant in climate dynamics even at these low concentrations. Human activity is by far the largest contributor to increases in CO2 concentrations. Water vapor, an abundant and powerful greenhouse gas, is not left out of climate models as contrarians have charged. Indeed CO2 absorbs some infrared wavelengths that water vapor does not so it adds heat to the atmosphere which causes it to take up more water vapor. Water vapor enters and exits the atmosphere much faster than CO2. It is CO2 that is the climate “forcing.” Claim 2) The hockey stick graph does not acknowledge the Medieval Warm Period around 1000 C.E. The hockey stick graph is corroborated by several lines of independent evidence including tree rings and ice cores. The magnitude and geographical extent of the Medieval Warm Period are not known with certainty. This period and the Little Ice Age between 1400 and 1700 C.E. may have been due to changes in solar radiance and other natural factors not seen today. Even if the world was warmer then it has no bearing on what is happening today. Claim 3) The Earth has been cooling for the last decade. That statement is statistically flawed. Ocean currents may cause temporary cooling but overall there is warming. Independent statisticians found only a small lull, with no real cooling over time. I think that since 2009 this is even more firm. Claim 4) The sun or cosmic rays are the real cause of global warming as Mars is warming too. Astronomical phenomena cause changes in solar radiation through a few long-term cycles. The largest actual uncertainty of past climate may well be the effects of aerosols, which can warm or cool. Even with these uncertainties it is certain that “human influence on climate exceeds that of any solar radiation.” Cosmic rays entering the atmosphere help to seed the formation of aerosols. Henrik Svensmark noted that high solar magnetic activity over the past 50 years has shielded the earth form cosmic rays and led to heating but that now has reversed so that we should now be cooling. While this is apparently plausible it does not explain why more heating occurs at night while greenhouse warming does. It also does not explain long-term trends and affect on clouds. Mars warming is based on a few measurements and is not well understood. It could be dust storms. Claim 5) Climatologists hide data. Consensus is irrelevant. The notion that global warming is a well orchestrated conspiracy is ridiculous. The science has been examined, reviewed, critiqued, etc. Claim 6) Climate alarmism benefits climate scientists. Another ridiculous assertion. Claim 7) Techno fixes such as geoengineering would be wiser than reducing carbon footprints. Bjorn Lomborg has advocated this view. Hansen points out that CO2 in the ocean will continue to heat the climate even if we stop emitting all of it now. Geoengineering could have some limited applications but would more likely be a desperate effort in the late stages of catastrophe. Regulatory approaches are probably much wiser and doable.

The section on Climate Talks begins with: Moving Beyond Kyoto by Jeffrey D. Sachs (Feb 2007). The Kyoto protocol was flawed since it left out developing countries which have since increased their emissions drastically. Here the author advocates long-term goals of say 450-550 ppm CO2 with further reductions by mid-century rather than short-term reductions sought in the Kyoto accords.

Next is Climate Talks Consensus: Cut Greenhouse Gas Emissions  by David Biello (Dec 2011). In South Africa in Dec 2011, 194 countries have agreed that a universal plan to cut carbon must be completed by 2015. Kyoto was extended. Nitrogen trifluoride was added to CO2, methane, nitrous oxide, sulfur hexafluoride, and perfluorocarbons, as a greenhouse gas. A fund to help poor countries to comply was set up. The goal was defined to hold temp to no more than 2 deg C rise but it is still unclear when, if, and how that will come about.

Next section is Solutions. First essay is: Ten Solutions for Climate Change by David Biello (Nov 2007). 1) Forego fossil fuels. This is obviously the most daunting challenge and is simply cureently not possible for most people in modernized societies. 2) Infrastructure upgrade. Buildings contribute about 43% of emissions. Much can be done to insulate and make energy use more efficient. Cement production is a major emissions source but new processes could reduce the energy needed to make it. 3) Move closer to work. Also cutting log distance travel, particularly airplane flights, would be useful. 4) Consume less. Think green, Buy in bulk. 5) Be efficient. Don’t waste. Do more with less. Use energy-saving products such as those that are Energy Star compliant. 6) Eat smart, Go Vegetarian. It is estimated that each meat-eating American produces 1.5 tons more greenhouse gases than their vegetarian peers. 7) Stop cutting down trees. Deforestation is responsible for about 20% of human-made greenhouse gas emissions. Improved agricultural practices and using sustainable wood products can help. 8) Unplug. Use efficient products. Unplug electronics not in use. This is hard to do for most people, including me. Perhaps someone could make a way for a switch to effect the unplugging. 9) One child. Making less humans means less consumers. 10) Future fuels. Renewable energy is not perfect and not cheap but is doable and sustainable in a lot of ways. Climate change offers us a planet-wide experiment, says the author.

Next is: Eric McAfee on Biofuels by the editors (April 2009). This is a Q and A. Cellulosic ethanol from agricultural waste aided by enzymes is discussed as a possible alternative. Funding and cost are difficult as these biofuels are not so economic. Next generation biofuels still have to compete with gasoline and diesel.

Can Captured Carbon Save Coal by David Biello (June 2009). Although there have been  tests, few CCS projects are on-line and this is because there is no real incentive or requirement. This may change with Obama’s new executive order on power plant emissions. The U.S. may have 100 years or more of CO2 sequestration capacity. The technology is doable but it costs. Successful projects stripping CO2 from natural gas fields and injecting it back into reservoirs have been successful. Enhanced oil recovery projects injecting CO2 are economic but the remaining potential is somewhat limited to dwindling fields. There is a fear that CO2 could suddenly escape and kill people as happened naturally near a lake in Cameroon in 1986 killing 1000 nearby villagers. But this is quite unlikely as modeling indicates CO2 has to be more than 10% of air to be hazardous and this would be difficult to achieve. A price on carbon would make CCS more plausible. With the new power plant rules it is one solution to keep coal going. Interestingly it is easier to capture CO2 from natural gas plants so if more or all coal is retired then more CO2 can be captured faster and cheaper from gas plants. Environmental groups like EDF and NRDC acknowledge that coal must be dealt with in order to make timely emissions reductions and CCS is one way of helping. Other emitting industries like cement, steel, and aluminum smelting could also utilize CCS. Estimates are only for a handful or maybe up to ten CCS-ready coal plants by 2020 but every little bit helps.

The Low-Carbon Diet by Christine Soares (March 2009). This one is about food. Food processing, packaging, energy-intensive agriculture, transportation, nitrogen runoff, and pesticide residues are just some of the emissions/waste/pollution issues with food. Organic, local, vegetarian, and sustainable food is more benign.

A Path to Sustainable Energy by 2030 by Mark Z Jacobson and Mark A. Delucchi (Aug 2010). Jacobson has been promoting renewable energy as feasible to totally replace fossil fuels, even appearing on Late Night with David Letterman. The problem is that to do his plan would require the most unified effort in human history. In that case it is more about confidence that renewables can work as the major and eventually only source of energy. Al Gore rather foolishly laid out a goal to have 100% carbon free electricity by 2018. That is not even remotely possible in any way. These guys lay out a plan with wind, water, and solar but the costs are astronomical. Batteries and hydrogen fuel cells would also be required. They point to re-tooled factories during WWII and our national highway system as precedents. Appliances would all need to be electric. Hydrogen produced by wind, water, and solar would power fuel cells to be burned by airplanes and industry. Their plan calls for 51% wind, 40% solar, and the rest water, tidal, and geothermal. Materials could be a problem such as rare earth neodymium required for wind turbine gear boxes. Development of gearless turbines would fix that problem. Solar panels require silver, and some rarer cadmium and copper minerals. Rare-earth metals for motors, lithium for batteries, and platinum for fuel cells are problematic and would require efficient recycling. A new infrastructure would be required with energy-on-demand in mind. With wind and solar the problems of intermittency, back-up power, and steady base supply (perhaps from water and geothermal) would have to be worked out for each of the tens of thousands of power plants required. Wind power is the cheapest but solar has gradually come down and has some useful localized and niche applications such as residential and district rooftop power that does not have to de transmitted far. Electric vehicles with lithium-ion or nickel metalhydride batteries can be cost effective when compared to even the current price of gasoline. Total cost for their plan would be around $100 trillion but they note that with current demand new fossil fuel power plants required would be $10 trillion. And the costs to health and the environment are drastically reduced. It would not be a government handout but an investment that would be paid back by the selling of the energy. At some point wind, water, and solar will become competitive in cost with fossil fuels, they say. Anticipating that time by building ahead would be a good strategy. Subsidies and carbon taxes would be needed for a while until the systems are in place. Feed-in tariffs would also be required but eventually the grid would need to buy power from the lowest bidder and feed-in tariffs would be phased out. Subsidies for fossil fuels and biofuels such as ethanol should be phased out, they say, to level the playing field. There would be losers as long-term sunk investments in old tech, fossil fuel power, and existing infrastructure would be lost. The authors think that the hurdle of technological feasibility for 100% renewables has been clearly crossed. Now, what is required is political will and leadership on this process. Unfortunately , getting most of the world to agree to something like this is a daunting task, but as projects come on line and renewables become more competitive and as fossil fuel supplies dwindle and their prices rise, it will happen. But will it happen soon enough?