In this fifth installment of our on-going series of interviews with some of the leading thinkers and scientists on the subject of energy, we interview Martin Hoffert.

Martin I. Hoffert is Professor Emeritus of Physics and former Chair of the Department of Applied Science at New York University.  He is a member of the American Geophysical Union (AGU), the American Institute of Aeronautics and Astronautics (AIAA) and was elected fellow of American Association for the Advancement of Science (AAAS).  I met Marty at the Foundation for the Future’s Energy Conference a couple of months ago and was struck by his passionate outspokenness on the energy issues confronting the world today.  Whether it was due to his emeritus stature, which allows him to speak without an institutional filter or just his nature, he was one of the most passionate and delightfully opinionated scientists at the conference.  Enjoy the following interview with Marty.

Please note there are also two links from YouTube that feature Marty.  I strongly recommend that you watch them. They are enjoyable.  One is from PBS and the other from CNN.


1. In your presentation at the Foundation for the Future’s “Energy Challenges:  The Next Thousand Years” you were quite emphatic about the urgency for humanity to change energy consumption, and the types of energy that is used.  Please elaborate and perhaps suggest timelines for this to occur. 

Hoffert:Avoiding a planet-changing global warming catastrophe is why we urgently need to transform the global energy system to a carbon-neutral one.  The clock is ticking. Absent the fossil fuel greenhouse this transformation could be deferred to the 22nd century or later. 

There’s enough energy in coal (more than twice oil and gas combined) to run high-tech civilization a few hundred years more; enough for electric power generation by conventional pulverized coal plants; enough for coal-derived synthetic liquid fuel powered motor vehicles and aircraft. Unfortunately, there’s also enough carbon in this coal that burning it is likely to drive climate back a hundred million years, when atmospheric CO2 levels were 3-4 times higher, global temperatures 10 degrees Celsius hotter, sea level 100 meters higher and both poles deglaciated. Dinosaurs and crocodiles roamed the warm polar latitudes of this middle-Cretaceous Earth. We’re well on the path to planet-changing from what Roger Revelle and Hans Seuss called our “grand geophysical experiment:” the transfer of hundreds of billions of tons of carbon in fossil fuels to atmospheric CO2. It’s already started. 

The good news is that three technology classes of carbon-neutral primary power in some combination could mitigate the worst impacts: (1) coal gasifiers driving integrated combined cycle power plants for electricity and hydrogen production with CO2 capture and storage in deep saline aquifers; (2) nuclear plants running on sufficiently abundant fissile fuels (i.e., U-233 bred from thorium) and eventually fusion; and (3) renewables, mainly solar and wind, along with appropriate transmission and storage technologies and smart, eventually global grids, perhaps superconducting, capable of matching electricity supply and demand load curves; and space solar power beaming energy collected in orbit to grid-interconnects worldwide for base load electricity. Zero point energy and cold fusion don’t make my list as I’ve not seen reliable evidence they could power the world. Improving the efficiency of primary energy conversion, transmission, storage and end use will certainly help. So-called “geoengineering” might also be needed for emergencies like “saving the arctic.” A near-term priority is efficicnt carbon-neutral propulsion for cars, trucks and aircraft now running on refined crude oil (see below). 

Fixing global warming will be hard. Just the ticket to revitalize this nation and the world. As JFK put it at the beginning of the Apollo Program, “We choose to go to the Moon (and do the other things) not because they are easy, but because they are hard. Because that goal will serve to mobilize the best of our energies and skills.” New energy systems won’t spring into existence by market forces alone. Coal is too cheap. We’ll need carbon taxes, perhaps revenue-neutral ones ramping up over time; “cap-and-trade” schemes like those in the EU; or Keynesian pump-priming with some combination of government and private sector management and contractors doing the work, as in Apollo and military weapons programs. In the civil sector we have the National Highway Act passed under a Republican president, Eisenhower, by which interstates are built and maintained with federal tax money. Right now, we most need a scientifically literate US president well-advised in energy and climate with the vision to initiate massive programs to research, develop, demonstrate, diffuse and deploy carbon-neutral energy worldwide. A brain trust of talented engineers and scientists should run these programs, not bean counters. 

An upbeat history lesson is the US mobilization to fight World War II begun in the midst of an economic depression with no significant military. By 1944, 50,000 planes a year were rolling off assembly lines. So too could wind turbines and solar modules. Funding is the least of our problems. Who remembers what WW II “cost” when the US ended-up economic superpower of “the American Century?” Does the question even make sense? Most needed now, as then, is a sense of urgency. Not paralytic terror, but a determination to face reality and get the job done. Political leaders should be banging on the table about this.  We simply can’t maintain our civilization of six billion plus without massive power sources. Two billion are kept from starvation by grace of the “green revolution” based on energy-hogging fertilizers. However dark the threat of global warming, I remain an optimistic techno-nerd, an eternal geek pushing forward with technology toward the light.

2.  In your presentation you talked about all the people who have, in years past, debunked global warming, citing incomplete scientific documentation.  Do you think, in light of recent information and a tipping point in awareness regarding global warming that this dialogue between those who see global warming as real and those who don’t is now essentially over?  Isn’t the overwhelming balance of scientific evidence pointing to both global warming, and humanity’s participation in it now irrefutable? 

Hoffert:Global warming is based on rock solid atmospheric physics. The same physics that explains the atmospheres of Venus, Earth, and Mars; and even of Saturn’s moon, Titan. The greenhouse effect which warms the surface of planets whose atmospheres contain infrared absorbing gases also explains why Earth is 33 degrees C warmer than it would be without them: Warm enough for life to have evolved and persisted 4 billion years on what would have otherwise been a frozen iceball. That additional global warming of Earth’s surface is now caused by humankind’s fossil fuel CO2, with more to come, is also settled science. An immense data base supports it: global networks of land and ocean surface temperatures, instrumental and paleoclimate records of atmospheric composition, radiosonde and satellite data, sea ice measurements, borehole records, tracers and temperature profiles measured in surface and deep oceans, compositions of gas bubbles and isotope-derived temperatures from polar icecores, and more. 

Ominously, accurate gravity anomaly satellite data that became available after the most recent IPCC report show Greenland and Antarctica melting much faster than predicted, most likely because of “albedo flip,” a positive feedback previously neglected in models in which dark meltwater absorbs sunlight faster than had been thought in glacial interiors. Amplified warming at high latitudes, heat penetrating the ocean, a cooling stratosphere as the troposphere warms, and other details are “fingerprints” that the recent warming is due to humans, not natural variations. There are influences on climate from volcanic aerosols and solar variability. But these have been carefully assessed and do not significantly contribute to the continuous temperature trend upwards like CO2 does. 

In a recent CNN debate during the Live Aid concerts to raise awareness of global warming I responded to a challenge to its reality — such a question would not likely have been asked in Europe — with a list of impacts. My opponent, from the Competitive Enterprise Institute, didn’t deny these — he being more intent on painting his “do-nothing-now” position as reasonable in comparison with the “alarmist” Gore. But the moderator observed that many Americans say global warming’s a lot of hooey, and that we cannot afford to ignore their views. This being Soundbite Land the segment ended before I could respond. I will here. However much climate change deniers say global warming’s hooey or a hoax, its reality is undeniable; documented in thousands of peer-reviewed journal articles; Intergovernmental Panel on Climate Change (IPCC) reports; well-written books [e.g., John Houghton’s, Global Warming: The Complete Briefing, 3rd edition (Cambridge University Press, 2004); Spenser Weart’s, The Discovery of Global Warming (Harvard University Press, 2003)]; and online information sources like where authoritative answers to questions about climate change can be found. 

There will always be those who challenge disturbing facts no matter how good the science. Many Americans don’t believe in evolution; some geologists don’t accept plate tectonics, and some think the NASA Moon missions were a hoax. Self-interest can also create cogitative dissonance between what one wants to believe and what is. Some smokers kept insisting smoking doesn’t cause cancer or heart disease after the Surgeon General’s Report. An African leader who perhaps can’t afford proper drugs holds that the HIV virus doesn’t cause AIDS. Should people die from disinformation and delusions?  So what if some don’t believe in global warming? They’re wrong. Survival of high tech civilization is at stake. Time to stop dithering and get serious about policies that could make a difference. 

3.    Do you believe in Peak Oil, and if so, what is your projected depletion date of the world’s petroleum reserves? 

Hoffert:We naked apes burn some 80 million barrels of oil a day; a rate that’s risen continuously since the first commercial well in Titusville, Pa, in 1859; also risen has been the global consumption rate of natural gas. Both curves will peak at some point and then decline as it becomes increasingly expensive in terms of energy and dollars to extract that extra barrel of oil or cubic meter of gas. There’s lots of dilute organic carbon in Earth’s crust, most of which isn’t worth getting. It’s concentrated hydrocarbons that are limited. Virtually all petroleum geologists agree we’re out of “conventional” oil and gas by the end of the century. The precise scenario by which this depletion occurs, and this is where “Peak Oil” comes in, based on the analysis in the 50s by petroleum geologist King Hubbert, is somewhat, but not very, uncertain.

In my opinion the global oil and gas peaks are here. They’re what’s driving recarbonization of fossil energy back to coal from oil and gas, a reversal of historic trends as total energy demand keeps rising and gas and oil get more expensive. Carbon dioxide emissions are rising faster than expected because coal produces more CO2 per unit of energy. Especially ominous for global warming are 850 new coal-fired power plants to be built by 2012 by the US, China and India that will overwhelm in the opposite direction Kyoto Protocol emission reductions by a factor of five.

4. What do you think are the most promising forms of energy to replace petroleum short term?  Why? 

Hoffert:I’m not totally negative, but not gushingly optimistic either, about carbon-neutral biofuels (ethanol, biodiesel, vegetable oil) as replacements for gasoline. With the possible exception of genetically altered algae, at any scale large enough to matter, biofuels compete for land with agriculture, reforestation and biodiversity preservation. By 2050 we’d need the area of all human agriculture to fuel our inferno of car, truck and aircraft engines. We don’t have it. Also, the net energy balance of biofuels (their chemical energy content relative to the energy needed to make them) is negative, or only slightly positive. Still, biofuels could be a bridge to a differently-energized global transport system; or a backup for mostly electric cars evolved from hybrids.

Near-term, I favor a massive shift in transportation to fuel-efficient, Prius technology level plug-in hybrid cars, busses and trucks, with off-peak and wind-powered battery charging when parked. This would be a big step forward that can be fast-tracked with the right policies. Hybrid cars and wind electricity are existing technologies that could cut oil consumption and CO2 from transportation big time in a decade. Slightly longer term, but on the horizon if costs can be cut, are ultralight car bodies and chassis made of composites, like the new Boeing Dreamliner aircraft, energy losses of both cars and planes being roughly proportional to mass. Wind electricity is nearly competitive with coal- and gas-fired plants at the busbar in the best locations like the Great Plains. High voltage DC transmission lines could convey it nationwide. We’ll need new “renewable friendly” electric grids in any case. Windpower could get a big boost by using it to recharge hybrid batteries thereby storing transient & intermittant power chemically at no cost to utilities.

By shifting more of the hybrid driving cycle to higher capacity, more powerful batteries, internal combustion would play a progressively smaller role, until biofuels might suffice as backup power to insure the range drivers want, but with near-zero net CO2 emissions. Battery technology is already experiencing a revolution with lithium ion and lithium polymer chemistries providing high energy and power densities. But they’re expensive. The lithium ion Tesla two-seater all-electric car is expected to sell for $90,000, mostly battery costs. Massive implementation of plugin hybrids should drive these costs down substantially by economies of scale and learning-by-doing. about long term?  Why? 

Hoffert:Longer-term, surface vehicles and aircraft might be powered carbon-neutrally by onboard hydrogen made from solar and wind energy, or coal-derived hydrogen with CO2 capture and storage — the latter being a goal of the US DoE FutureGen program. Also possible with air capture and storage of CO2 are carbon-neutral liquid hydrocarbon fuels for transportation from crude oil, shale and even coal. Cost-effectively capturing CO2 directly from the atmosphere is much harder than from centralized power plants where it’s much more concentrated, and much easier to separate. Ultimately carbon removed from the air would be stored as pressurized or dissolved CO2 in presumably leak-proof reservoirs, or as carbonate minerals that might, for example, be used as building materials. Despite hydrogen hoopla, few hydrogen fueling stations for cars exist, and no commercial or military airports have hydrogen tank farms ready to go should hydrogen aircraft become available.  Hydrogen’s in the picture, but not the bright hope it seemed a few short years ago. Some out-of-the-box approaches for transportation look promising and exciting like transmitting energy wirelessly to cars from roadbeds, or from space to aircraft. Venture capitalists are willing to role the dice for projects with big multipliers that pay off (if they do) in three to five years at most. Internationally, governments are evidently prepared to shell out for fifty year time scale for big enough ideas like fusion: The International Thermonuclear Experimental Reactor (ITER) program will cost some $20 billion though its advocates don’t project as a commercial power source before mid-century. To address global warming meaningfully we most need most R & D investments aimed at the funding “Valley of Death” in the five to thirty year time scale. 

6. role does Solar Space Energy play in this mix?  Some have suggested that it can largely solve the energy demands of humanity by the end of this century, do you agree?

Hoffert:The short answer is that space solar power (SSP) is more feasible and more technologically mature as a source of base load electricity than fusion; even though fusion has its $20 billion ITER and SSP is effectively unfunded. This imbalance in investment, very possibly in the wrong direction, is more the result of lack of strategic-placed champions than than intrinsic merit. SSP is closer than fusion because it’s based on well-understood science and existing technologies (solar cells, solar concentrators, microwave and laser beamers, launch vehicles with access to GEO). High capital cost to first power rooted in their underlying physics is a major limitation to both fusion and SSP, but lower entry costs are possible with lasers, as opposed to microwaves. The atmosphere is transparent to laser and microwave beams — why we see the stars with our eyes and astronomers see them radiotelescopes. But laser wavelengths are 100,000 time shorter, and the smaller components associated with the much less diffractive lasers make them in my opinion a much better place to start.

7. important is conservation?  What can we immediately undertake as individuals, as a country and on the global level? 

Hoffert:We do of course include improvements in energy efficiency in our analyses; which, along with continually less energy consumptive lifestyle changes, is reflected in declining energy intensity (primary energy consumed per unit GDP). In the twentieth century energy intensity declined globally on average about 1%/yr. Analyses by Green and Lightfoot indicate that in this century continued 1 %/yr E/GDP decline is a likely upper limit because of thermodynamic and other factors. A 40% reduction in energy consumption from efficiency and lifestyle changes by 2050 is implied by the magic of compound interest in our 1%/year reduction in our “business as usual” scenario, which accounts for the difference between GDP growing 3% per year, and energy demand growing only 2% per year. Extreme energy efficiency advocates like Amory Lovins assert that there’s no limit on how much GDP can be extracted per unit of primary energy, but frankly I find these arguments unconvincing. you believe in carbon credits?  Are some better than others? 

Hoffert:Carbon emission credits as part of a “cap-and-trade” scheme can play a role but as I said earlier I view the climate/energy challenge mainly as an engineering problem, with money the least of our problems. The idea of setting up a market in tradable emission permits reminds me too uncomfortably of the Enron, whose CEO, Kenneth Lay, who presided over this Ponzi scheme, was a respected Ph.D in economics. Indeed, Enron lobbied the Bush administration to ratify Kyoto so they could get in on the emission trading action.  I had better not expound to much on this topic as I’m already in enough trouble with economists, even though some of them are my best friends! the last day of the conference we identified three things that were considered the most important things to work on going forward:  issues of energy storage,  public awareness of the energy crisis, and the creation of a global energy coordinating body to facilitate and oversee the new world of alternative energy and energy conservation.  What are your thoughts on these three issues and which one is most urgent? 

Hoffert:A pundit has observed that “The best thing about democracy is that everyone and vote; and the worst thing about democracy is that everyone can vote.” So long as we’re living in a democracy an educated public is the key to sustainable energy policy. We need better science education, more informed science journalists and bloggers, scientists and engineers more willing to speak out, and a administration pro-active on climate and energy that clearly understands these issues.  So public awareness is the most important goal near term. Let’s all start working on it now. else would you like to comment on, or suggest to readers of this blog? 

Avoiding dangerous human interference with the climate system is the goal of the UN Framework Climate Convention. Sustainable planetary power sources are likewise needed to solve most of humankind’s other problems (food, poverty, disease, fresh water, education, democracy, tribal aggression, . . .). If the fossil fuel energy system is to be phased-out in a half-century, global warming must necessarily trump humanity’s other problems in priority in the short run. The truth is that we’ll need an infrastructure of global scale, carbon-neutral & sustainable power in place by midcentury or there may not be a long term for our high tech civilization of six billion plus. Our economy runs on fossil fuel the way the Roman Empire ran on slavery and the British Empire on colonialism. 

There is growing recognition worldwide (even in the US) that global warming is a problem, but it’s its perceived too nonspecifically and unrelated to policies that might actually curb it in time to matter. It’s pathetic and self-destructive, for example, that CO2 emissions from conventional coal power plants in the works by the US, India and China (none of whom have agreed to CO2 emission targets) will overwhelm in the opposite direction Kyoto reductions by a factor of five by 2012, and that there’s scarcely a peep over the climatic disaster this bodes for the second half of the 21st century. 

 The Herculean scale of climate/energy challenge is unprecedented. But an effective response is doable in my opinion if we have the appropriate sense of urgency. Climate scientists and glaciologists are converging on a limit of less than 2 degrees Celsius global warming to prevent irreversible icecap melting with global inundation, implying a near-phaseout of fossil fuel CO2 emissions by mid-century from the governing climate, carbon cycle and energy equations — “the cold equations of global warming.” We have to be on track to emission phase out in fifty years to get there.  Marty, thank you very much!