The relative contribution of waste heat from power plants to global warming

Evidence on global climate change, being caused primarily by rising levels of greenhouse gases in the atmosphere, is perceived as fairly conclusive. It is generally attributed to the enhanced greenhouse effect, resulting from higher levels of trapped heat radiation by increasing atmospheric concentrations of gases such as CO₂ (carbon dioxide). Much of these gases originate from power plants and fossil fuel combustion. However, the fate of vast amounts of waste heat rejected into the environment has evaded serious scholarly research. While 1 kWh electricity generation in a typical condensing coal-fired power plant emits around 1 kg of CO₂, it also puts about 2 kWh energy into the environment as low grade heat. For nuclear (fission) electricity the waste heat release per kWh is somewhat higher despite much lower CO₂ releases. This paper evaluates the impact of waste heat rejection combined with CO₂ emissions using Finland and California as case examples. The immediate effects of waste heat release from power production and radiative forcing by CO₂ are shown to be similar. However, the long-term (hundred years) global warming by CO₂-caused radiative forcing is about twenty-five times stronger than the immediate effects, being responsible for around 92% of the heat-up caused by electricity production.     

Seven steps to curb global warming

Based on best current estimates that the world needs to reduce global carbon dioxide emissions by 70% by 2050, and that there is at best a 10-year window of opportunity available to initiate the enormous changes needed, this paper proposes a set of seven self-contained steps that can be taken at a global level to tackle the problem with some prospect of success. The steps are self-financing and practicable, in that they are based on existing technologies. They involve agreement to create a new international agency charged with formulating and policing a global carbon pricing regime; a complementary step involving global monitoring of greenhouse gas emissions utilizing satellite resources; taking steps to compensate developing countries for preserving rainforest as carbon sinks; the dismantling of newly created trade barriers holding back global trade in biofuels; global promotion of a transition to renewable sources of electricity through facilitation of grid interconnections with independent power producers; a global moratorium on the building of new coal-fired power stations; and recycling of carbon revenues to promote uptake of renewable energy sources in developing countries, particularly Brazil, India and China. Taken as a group, it is argued that these steps are both necessary and sufficient. They call for institutional innovations at a global level that are politically difficult but feasible, given the magnitude of the problems addressed.     

Economic global warming potentials

A reformulation of global warming potentials is propounded, that combines the time-horizon and discounting definitions, and covers both ordinary atmospheric forcing (via greenhouse gases) and its rate-of-change. Insofar as GWPs are used to guide investment and socioeconomic choices, there is merit in adopting cost-benefit techniques. The parametric equivalence of the two definitions applies for the ordinary atmospheric forcing; but for its rat-of-change, only the discounting definition gives realistic results, as shown in application to methane, a short-lived greenhouse gas.     

Fossil-fuel constraints on global warming

In 2008 and 2009 two papers by Kharecha and Hansen and by Nel and Cooper examined possible fossil energy availability and energy consumption scenarios and consequences for future climate. The papers yield somewhat similar results regarding atmospheric CO₂ levels, but they reach substantially different conclusions regarding future climate change. Here, we compare their methods and results. Our work shows that Nel and Cooper's paper significantly underestimates future warming. Nel and Cooper conclude that even if all the available fossil fuels would be burned at the maximum possible rate during this century, the consequent warming would cap at less than 1 °C above the 2000 level. We find that – under Nel and Cooper's assumption of an intensive exploitation of fossil fuels – the global temperature in 2100 will likely reach levels which would lead to severely damaging long-term impacts.     

On the global warming problem due to carbon dioxide

The subject of global warming due to the increased use of fossil fuels is analyzed using a modification of the predator prey equations. The results of the calculation indicate that both the fossil fuels and civilization will both become extinct as time increases.     

Does fossil fuel combustion lead to global warming?

Tropospheric sulfate aerosols produced by atmospheric oxidation of SO₂ emitted from fossil fuel combustion scatter solar radiation and enhance the reflectivity of clouds. Both effects decrease the absorption of solar radiation by the earth-atmosphere system. This cooling influence tends to offset the warming influence resulting from increased absorption of terrestrial infrared radiation by increased atmospheric concentrations of CO₂. The sulfate forcing is estimated to be offsetting 70% of the forcing by CO₂ derived from fossil fuel combustion, although the uncertainty of this estimate is quite large--range 28 to 140%, the latter figure indicating that the present combined forcing is net cooling. Because of the vastly different atmospheric residence times of sulfate aerosol (about a week) and CO₂ (about 100 years), the cooling influence of sulfate aerosol is exerted immediately, whereas most of the warming influence of CO₂ is exerted over more than 100 years. Consequently the total forcing integrated over the entire time the materials reside in the atmosphere is net warming, with the total CO₂ forcing estimated to exceed the sulfate forcing by a factor of 4 (uncertainty range 2 to more than 10). The present situation in which the forcing by sulfate is comparable to that by CO₂ is shown to be a consequence of the steeply increasing rates of emissions over the industrial era.     

Hydrogen no longer a high cost solution to global warming: New ideas

This paper contains brief statements about three new low-cost methods of obtaining clean hydrogen in massive amounts.

In the first method, new technology for converting solar energy and water to hydrogen at a price of $2.50 for an amount of hydrogen equal in first law energy to that in a gallon of gasoline seems to follow from a company's announcement of their new technology, already working, in one fully industrialized plant, producing electricity at a price corresponding to that from coal.

In the second method, pure hydrogen (no accompanying CO₂) can be obtained from natural gas and heat. The cost would be a little less than that of the low-cost hydrogen from water decomposition (and avoid storage of hydrogen for the 18 h/day of zero solar light).

In the third method, CO₂ is extracted from the atmosphere and combined chemically with the low-cost hydrogen to produce methanol. On being used to produce heat or electricity (fuel cell), CO₂ is left over. However, the amount of CO₂, thus added to the atmosphere is just equivalent to the amount removed. The presence of low-cost hydrogen from water means that the resulting methanol will also be of low cost and be a cure for global warming without a radical change of distribution method.     

Designing a friendly space for technological change to slow global warming

What is the best strategy to encourage research and development on new energy technologies in a market economy? What steps can ensure a rapid and efficient transition to an economy that has much lower net carbon emissions? This paper shows that, under limited conditions, a necessary and sufficient condition for an appropriate innovational environment is a universal, credible, and durable price on carbon emissions. Such a price would balance the marginal damages from carbon emissions against the marginal costs of abating emissions; it should not contain a correction factor for inducing technological change. This result, which the paper calls “price fundamentalism,” applies principally to the market-oriented part of research and innovation. It is subject to qualifications regarding the efficacy of intellectual property protection and the proper level of carbon prices, and it applies primarily to market sectors. The role of appropriate prices on emissions is a central part of public policies to encourage technologies to combat global warming.     

The case for renewables apart from global warming

The outcome of COP15, the conference on climate change in Copenhagen, was the Copenhagen Accord which was recognised by the 193 countries that attended. The Accord set no compulsory limits on carbon emissions, and none of the countries that introduced it – USA, China, India [with Brazil and South Africa] – has signed the Annexe to the Kyoto Agreement, committing them to limit their emissions. Climate change is only of secondary importance to them compared with eradicating poverty. Nevertheless three of these countries are in the lead currently for installing renewables, far ahead of most of those [only 37 out of 187 countries world-wide] who are committed to limiting their emissions. This paper explains why. The main function of renewable energy is to save fuel, thereby reducing energy imports and maintaining security of energy supplies without the need to fight world wars over them. Also, being capital intensive with all the money paid up-front, renewables avoid the price fluctuations that bedevil the oil and other fossil fuel industries. As capacity is doubling every 3 years, renewables prices will come down with savings of scale, so wind power in particular will soon be the cheapest form of power.     

Expected halt in the current global warming trend?

The variation patterns of global temperature were considerably turbulent from about 1870 up to 1940. Then just after 1940 these patterns underwent a sunspot-related change and adopted to relatively less turbulent variability. It is established here that these global temperature patterns are currently in the process of undergoing a sunspot-related change from the post-1940 relatively less turbulent variability back into relatively more turbulent variability. This apparently imminent state of more turbulent variability is expected to stop and at least slightly reverse the global warming trend, which has been going on since about 1965. Besides, it is shown separately that the mean of ‘global mean temperature variations’ reaches the next peak at about the year 2005 after which it will expectedly be on a decreasing trend. Finally, it is shown that, contrary to projections made in the Third IPCC Assessment Report, Greenland is currently in an ongoing cooling trend which is expected to last up to at least the year 2035.     

地球变暖动态特性及滞后现象分析

工业生产过程中排放的温室气体会造成全球变暖现象,但全球变暖与工业排放在时间上具有一定的滞后效应.通过分析地球、大气、太阳三者热平衡体系的辐射换热,建立了地球及其大气的动态数学模型;利用此模型考察了造成地球温度变化的主要原因和变暖滞后的现象.结果表明:工业温室气体的过度排放会造成大气对地球辐射的吸收系数提高,导致地球温度升高;同时,太阳辐射能量增加,地球和大气对太阳辐射吸收增加,导致地球温度升高.结合近年来人为因素造成的地球温度升高现象进行了定量热分析,预测了温室气体CO2体积分数线性增加条件下的地球温度走势.     

How the next US president should slow global warming

This paper addresses the energy technologies and policies that the next US president should immediately implement to slow global warming. Increased reliance on renewable energy through deployment of a National Renewable Portfolio Standard will help meet increased electrical demand in a sustainable way. Carbon regulation through an internationally fungible cap and trade system will help make renewables more cost competitive with conventional energy. Mandating National Energy Efficiency Portfolio Standards will also help decrease electrical demand and reduce the need for large investments in new generation. Within the transportation sector, plug-in hybrid and electric vehicles should be rapidly deployed to shift this sector's liquid fuel requirements to the electrical grid.     

Constraints of fossil fuels depletion on global warming projections

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO₂ concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO₂ emissions until 2200 are derived. Using the coupled gas–cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO₂ concentration might increase up to about 480 ppm (445–540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 °C (0.9–1.6 °C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels.     

Testing the hypothesis hydrogen jets may significantly contribute to global warming through jets contrails

It has been claimed that hydrogen aviation may still significantly contribute to global warming through jets contrails, as hydrogen jets produce more contrails than jets fueled with kerosene. The claim, based on modeling exercises, can be tested via the Covid-19 experiment. Since March 2020, air traffic has been severely disrupted because of the pandemic. This has been true especially in Australia, the hermit country where citizens have been practically prevented from leaving or returning, with international air travel dramatically reduced. Analysis of the surface temperature data about international airports and air traffic from Australia provides the opportunity to test one of the hypotheses formulated about jet contrails' contribution to global warming. It is shown as opposed to previous claims, jet contrails are not responsible for reducing the difference between the maximum and minimum daily temperatures close to airports. Compared to the last 9 months of 2019, with air traffic normal, during the last 9 months of 2020 of highly disrupted flights, the difference in between the maximum and minimum temperatures in Sydney and Melbourne airports, has not been larger, but smaller by about 1 °C. The reduction in the difference between temperatures has been also smaller in Brisbane airport, but only at about 0.22 °C. We conclude as the claim adoption of hydrogen as an aviation fuel may produce global warming through the contrails mechanism is likely wrong. The contrails effect is everything but well understood and quantified with accuracy, and poorly represented in climate models. The contrails contribution to global warming is expected to be minor, and it should not void the value of hydrogen as a future renewable fuel free of CO₂ emissions.     

The potential role of hydrogen as a sustainable transportation fuel to combat global warming

Hydrogen is recognized as a key source of the sustainable energy solutions. The transportation sector is known as one of the largest fuel consumers of the global energy market. Hydrogen can become a promising fuel for sustainable transportation by providing clean, reliable, safe, convenient, customer friendly, and affordable energy. In this study, the possibility of hydrogen as the major fuel for transportation systems is investigated comprehensively based on the recent data published in the literature. Due to its several characteristic advantages, such as energy density, abundance, ease of transportation, a wide variety of production methods from clean and renewable fuels with zero or minimal emissions; hydrogen appears to be a great chemical fuel which can potentially replace fossil fuel use in internal combustion engines. In order to take advantage of hydrogen as an internal combustion engine fuel, existing engines should be redesigned to avoid abnormal combustion. Hydrogen use in internal combustion engines could enhance system efficiencies, offer higher power outputs per vehicle, and emit lower amounts of greenhouse gases. Even though hydrogen-powered fuel cells have lower emissions than internal combustion engines, they require additional space and weight and they are generally more expensive. Therefore, the scope of this study is hydrogen-fueled internal combustion engines. It is also highlighted that in order to become a truly sustainable and clean fuel, hydrogen should be produced from renewable energy and material resources with zero or minimal emissions at high efficiencies. In addition, in this study, conventional, hybrid, electric, biofuel, fuel cell, and hydrogen fueled ICE vehicles are comparatively assessed based on their CO₂ and SO₂ emissions, social cost of carbon, energy and exergy efficiencies, fuel consumption, fuel price, and driving range. The results show that when all of these criteria are taken into account, fuel cell vehicles have the highest average performance ranking (4.97/10), followed by hydrogen fueled ICEs (4.81/10) and biofuel vehicles (4.71/10). On the other hand, conventional vehicles have the lowest average performance ranking (1.21/10), followed by electric vehicles (4.24/10) and hybrid vehicles (4.53/10).