• Energy Research

The global environmental imperative demands urgent actions on ecological stabilization, yet the global scale of such actions is persistently insufficient. This calls for investigating why the world economy appears to be so fearful of any potential environmental expenditure. Using the formalism of Lyapunov potential function it is shown that the stability principles for biomass in the ecosystem and for employment in economics are mathematically similar. The ecosystem has a stable and unstable stationary state with high (forest) and low (grasslands) biomass, respectively. In economics, there is a stable stationary state with high employment in mass production of conventional goods sold at low cost price, and an unstable stationary state with lower employment in production of novel products of technological progress sold at higher prices. An additional stable state is described for economics with very low employment in production of life essentials, such as energy and raw materials that are sold at greatly inflated prices. In this state the civilization pays 10% of global GDP for energy produced by a negligible minority of the working population (currently ∼0.2%) and sold at prices exceeding the cost price by 40 times, a state when any extra expenditures of whatever nature appear intolerable. The reason lies in the fundamental shortcoming of economic theory, which allows for economic ownership over energy sources. This is shown to be equivalent to equating measurable variables of different dimensions (stores and fluxes), which leads to effective violation of the laws of energy and matter conservation in modern economics.

The prevailing scientific approach to investigating and understanding the environmental consequences of human-induced global change is underpinned by two basic biological principles. First, the principle that species genetically adapt to changing environment conditions. Second, the principle that nutrients present in the environment in the smallest relative concentrations limit biological productivity. We contend that both principles have been formulated based on the results of investigations into either artificially selected organisms, or anthropogenically perturbed landscapes. In both these cases, organisms are studied outside their natural ecological niche. We argue that natural ecosystems do not conform to the above two principles. Non-perturbed biota of natural ecological communities form and maintain optimal environment conditions by buffering the flux of primary environmental resources that would otherwise randomly fluctuate as the result of purely physical processes. In such a biotically-mediated environment the availability of nutrients does not limit biological productivity. Critically, the capacity of the biota to regulate local environment conditions obviates the need for species to continually adapt to random environmental fluctuations. We illustrate how the failure to distinguish between the functioning of perturbed and unperturbed biota prevents the development of policies and strategies that will lead to the long term resolution of the global ecological crisis.

AbstractIn their paper “The tropospheric land–sea warming contrast as the driver of tropical sea level pressure changes,” Bayr and Dommenget proposed a simple model of temperature-driven air redistribution to quantify the ratio between changes of sea level pressure ps and mean tropospheric temperature Ta in the tropics. This model assumes that the height of the tropical troposphere is isobaric. Here problems with this model are identified. A revised relationship between ps and Ta is derived governed by two parameters—the isobaric and isothermal heights—rather than just one. Further insight is provided by the earlier model of Lindzen and Nigam, which was the first to use the concept of isobaric height to relate tropical ps to air temperature, and they did this by assuming that isobaric height is always around 3 km and isothermal height is likewise near constant. Observational data, presented here, show that neither of these heights is spatially universal nor does their mean values match previous assumptions. Analyses show that the ratio of the long-term changes in ps and Ta associated with land–sea temperature contrasts in a warming climate—the focus of Bayr and Dommenget’s work—is in fact determined by the corresponding ratio of spatial differences in the annual mean ps and Ta. The latter ratio, reflecting lower pressure at higher temperature, is significantly impacted by the meridional pressure and temperature differences. Considerations of isobaric heights are shown to be unable to predict either spatial or temporal variation in ps. As noted by Bayr and Dommenget, the role of moisture dynamics in generating sea level pressure variation remains in need of further theoretical investigations.

Abstract. Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in the lower atmosphere. This decline occurs up to a certain height, which ranges from 3 to 4 km for surface temperatures from 10 to 30 °C. We then estimate the horizontal pressure differences associated with water vapor condensation and find that these are comparable in magnitude with the pressure differences driving observed circulation patterns. The water vapor delivered to the atmosphere via evaporation represents a store of potential energy available to accelerate air and thus drive winds. Our estimates suggest that the global mean power at which this potential energy is released by condensation is around one per cent of the global solar power – this is similar to the known stationary dissipative power of general atmospheric circulation. We conclude that condensation and evaporation merit attention as major, if previously overlooked, factors in driving atmospheric dynamics.

International audience

The nature of scaling between the organismal basal metabolic rate B and its body mass M, BpM, is currently an important focus of debates in theoretical biology (Whitfield, 2001). For decades, it has been widely accepted that a1⁄4 3/4 for virtually all groups of organisms (Hemmingsen, 1960; Kleiber, 1961). A novel approach developed by West, Brown & Enquist (1997) (WBE) explains the value of a1⁄4 3/4 (instead of 2/3 that is to be expected from basic dimensional considerations) by noting the fractal-like space-filling structure of networks that transport materials within living bodies. However, the agreement about the ubiquity of a1⁄4 3/4 in the living world has recently been seriously challenged by extensive analyses of data unavailable at the time of adopting the ‘‘3/4 rule’’. Dodds et al. (2001) showed that a1⁄4 0.67 for 357 mammalian species with mass less than 10 kg and a1⁄4 0.71 for the total of 391 species studied by Heusner (1991), while for birds a1⁄4 0.66 for the 398 species studied by Bennett & Harvey (1987). For unicellular organisms, a re-analysis of Hemmingsen’s (1960) data for 17 species by Prothero (1986) showed that a varies from 0.60 to 0.75 depending on which taxonomic groups are considered. Similarly, based on 554 observations for 108 species of Protozoa, Vladimirova & Zotin (1985) reported values of a from