James E. Lovelock

Bio: James E. Lovelock is an academic researcher from University of Reading. The author has contributed to research in topics: Gaia hypothesis & Atmosphere. The author has an hindex of 52, co-authored 130 publications receiving 17525 citations. Previous affiliations of James E. Lovelock include Baylor University & National Institute for Medical Research.

Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate

Abstract: The major source of cloud-condensation nuclei (CCN) over the oceans appears to be dimethylsulphide, which is produced by planktonic algae in sea water and oxidizes in the atmosphere to form a sulphate aerosol Because the reflectance (albedo) of clouds (and thus the Earth's radiation budget) is sensitive to CCN density, biological regulation of the climate is possible through the effects of temperature and sunlight on phytoplankton population and dimethylsulphide production. To counteract the warming due to doubling of atmospheric CO2, an approximate doubling of CCN would be needed.

Gaia, a new look at life on earth

Abstract: In this classic work that continues to inspire its many readers, Jim Lovelock puts forward his idea that the life of earth functions as a single organism. Written for non-scientists, Gaia is a journey through time and space in search of evidence with which to support a new and radically different model of our planet. In contrast to the conventional belief that living matter is passive in the face of threats to its existence, the book explores the hypothesis that the Earth's living matter - air, ocean, and land surfaces, forms a complex system which has the capacity to keep Earth a fit place for life. Since Gaia was first published, many of Jim Lovelock's predictions have come true and his theory has become a hotly argued topic in scientific circles. In a new Preface to this revised impression, he outlines the present state of the debate.

Prevention of Freezing Damage to Living Cells by Dimethyl Sulphoxide

Abstract: Polge, Smith and Parkes1 first reported the protective action of glycerol against the adverse effects on spermatozoa of freezing and thawing. Lovelock2 found that the protective action of glycerol was shared with a number of other neutral solutes of low molecular weight, including methanol, acetamide and glyceryl monoacetate. Using the extent of haemolysis of red blood-cells as a measure of damage by freezing, it was concluded that the principal protective action of the neutral solutes was a simple consequence of their ability to prevent the excessive concentration of electrolytes and other substances that otherwise occurs on freezing. The protective property is limited to substances that are in themselves not toxic, have a low molecular weight, a high solubility in aqueous electrolyte solutions and an ability to permeate living cells. The number of solutes capable of fulfilling these conditions is small, and so far glycerol most closely approaches the ideal protective agent. Some cells, however, are impermeable to glycerol, for example, bovine red blood cells, and with these glycerol is of little use in their preservation by cold storage. An alternative solute with a greater permeability to living cells is dimethyl sulphoxide. This communication reports the protective action of dimethyl sulphoxide against freezing damage to human and bovine red blood cells and to bull spermatozoa.

Atmospheric Dimethyl Sulphide and the Natural Sulphur Cycle

Abstract: ALL models of natural processes for the transfer of sulphur on a global scale1–4 require some volatile or gaseous sulphur compound to complete the cycle by providing a vehicle for the transfer of sulphur from the sea through the air to the land surfaces. In the past, this role has been assigned to H2S and an average atmospheric concentration of 2×10−10 by volume satisfied the mass transfer needs of the models. Attempts to detect the presence of these concentrations of H2S have always failed and, more important, the ocean surface waters are much too oxidizing to permit the existence of H2S at concentrations sufficient to sustain an atmospheric equilibrium concentration of 2×10−10 by volume. Many elements form volatile methyl derivatives; Challenger5 reported that many living systems produced dimethyl sulphide (DMS), and that prominent among them were marine algae. Here we suggest that DMS is the natural sulphur compound which fills the role originally assigned to H2S; that of transferring sulphur from the seas through the air to land surfaces.

Atmospheric homeostasis by and for the biosphere: the gaia hypothesis

Abstract: During the time, 3.2 × 10 9 years, that life has been present on Earth, the physical and chemical conditions of most of the planetary surface have never varied from those most favourable for life. The geological record reads that liquid water was always present and that the pH was never far from neutral. During this same period, however, the Earth's radiation environment underwent large changes. As the sun moved along the course set by the main sequence of stars its output will have increased at least 30% and possibly 100%. It may also have fluctuated in brightness over periods of a few million years. At the same time hydrogen was escaping to space from the Earth and so causing progressive changes in the chemical environment. This in turn through atmospheric compositional changes could have affected the Earth's radiation balance. It may have been that these physical and chemical changes always by blind chance followed the path whose bounds are the conditions favouring the continued existence of life. This paper offers an alternative explanation that, early after life began it acquired control of the planetary environment and that this homeostasis by and for the biosphere has persisted ever since. Historic and contemporary evidence and arguments for this hypothesis will be presented. DOI: 10.1111/j.2153-3490.1974.tb01946.x

A safe operating space for humanity

Abstract: Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockstrom and colleagues.

The Problem of Pattern and Scale in Ecology: The Robert H. MacArthur Award Lecture

Abstract: This book is the second of two volumes in a series on terrestrial and marine comparisons, focusing on the temporal complement of the earlier spatial analysis of patchiness and pattern (Levin et al. 1993). The issue of the relationships among pattern, scale, and patchiness has been framed forcefully in John Steele’s writings of two decades (e.g., Steele 1978). There is no pattern without an observational frame. In the words of Nietzsche, “There are no facts… only interpretations.”

Planetary boundaries: Exploring the safe operating space for humanity

Abstract: Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change (CO2 concentration in the atmosphere <350 ppm and/or a maximum change of +1 W m-2 in radiative forcing); ocean acidification (mean surface seawater saturation state with respect to aragonite ≥ 80% of pre-industrial levels); stratospheric ozone (<5% reduction in O3 concentration from pre-industrial level of 290 Dobson Units); biogeochemical nitrogen (N) cycle (limit industrial and agricultural fixation of N2 to 35 Tg N yr-1) and phosphorus (P) cycle (annual P inflow to oceans not to exceed 10 times the natural background weathering of P); global freshwater use (<4000 km3 yr-1 of consumptive use of runoff resources); land system change (<15% of the ice-free land surface under cropland); and the rate at which biological diversity is lost (annual rate of <10 extinctions per million species). The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social-ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the "planetary playing field" for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.

sources and effects of ionizing radiation

Abstract: NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …

Stratospheric sink for chlorofluoromethanes: chlorine atomc-atalysed destruction of ozone

Abstract: Chlorofluoromethanes are being added to the environment in steadily increasing amounts. These compounds are chemically inert and may remain in the atmosphere for 40–150 years, and concentrations can be expected to reach 10 to 30 times present levels. Photodissociation of the Chlorofluoromethanes in the stratosphere produces significant amounts of chlorine atoms, and leads to the destruction of atmospheric ozone.