Related papers: Do we have enough air?
In temperate climates, mortality is seasonal with a winter-dominant pattern, due in part to pneumonia and influenza. Cardiac causes, which are the leading cause of death in the United States, are also winter-seasonal although it is not…
Depletion of natural and artificial resources is a fundamental problem and a potential cause of economic crises, ecological catastrophes, and death of living organisms. Understanding the depletion process is crucial for its further control…
The general circulation of the atmosphere determines the long-term variability of weather processes. This circulation is driven by the temperature differences between the poles and the equator, causing air to move along the Earth's surface.…
It is shown that, contrary to an existing claim, the near equality between the lifetime of the sun and the timescale of biological evolution on earth does not necessarily imply that extraterrestrial civilizations are exceedingly rare.…
Once carbon emission neutrality and other sustainability goals have been achieved, a widespread assumption is that economic growth at current rates can be sustained beyond the 21st century. However, even if we achieve these goals, this…
JWST observations of the 7-planet TRAPPIST-1 system will provide an excellent opportunity to test outcomes of stellar-driven evolution of terrestrial planetary atmospheres, including atmospheric escape, ocean loss and abiotic oxygen…
The concise letter points out that the estimates of the global potential of wind power exceeds the amount of kinetic energy in the relevant layer of atmosphere by far more than an order of magnitude. Originally submitted to the Letters…
Element synthesis which started with p-p chain has resulted in several specific characteristics including lack of any stable isotope having atomic masses 5 or 8. The carbon to oxygen ratio is fixed early by the chain of coincidences. These,…
Life arose on Earth sometime in the first few hundred million years after the young planet had cooled to the point that it could support water-based organisms on its surface. The early emergence of life on Earth has been taken as evidence…
We discuss how greenhouse gases affect radiation transfer in Earth's atmosphere. We explain how greenhouse gases like water vapor or carbon dioxide, differ from non-greenhouse gases like nitrogen or oxygen. Using simple thermodynamics and…
Understanding processes that determine the global circulation of the atmosphere is necessary for long-term weather forecasting and climate studies which are critical for ensuring energy security. Processes in the atmosphere depend on many…
Mars has a thin (6 mbar) CO2 atmosphere currently. There is strong evidence for paleolakes and rivers formed by warm climates on Mars, including after 3.5 billion years (Ga) ago, which indicates that a CO2 atmosphere thick enough to permit…
The climate of early Mars remains a topic of intense debate. Ancient terrains preserve landscapes consistent with stream channels, lake basins, and possibly even oceans, and thus the presence of liquid water flowing on the Martian surface 4…
Competing geophysical/geochemical hypotheses for how Earth's surface became oxygenated - organic carbon burial, hydrogen escape to space, and changes in the redox state of volcanic gases - are examined and a more biologically-based…
Recently, transmission spectroscopy in the atmospheres of the TRAPPIST-1 planets revealed flat and featureless absorption spectra, which rule out cloud-free hydrogen-dominated atmospheres. Earth-sized planets orbiting TRAPPIST-1 likely have…
A habitable zone of a star is defined as a range of orbits within which a rocky planet can support liquid water on its surface. The most intriguing question driving the search for habitable planets is whether they host life. But is the age…
Understanding the lifetime of CO2 in the atmosphere is critical for predictions regarding future climate changes. A simple mass conservation analysis presented here generates tight estimations for the atmosphere's retention time constant.…
Present-day Mars is cold and dry, but mineralogical and morphological evidence shows that liquid-water existed on the surface of ancient Mars. In order to explain this evidence and assess ancient Mars's habitability, one must understand the…
Habitability is a measure of an environment's potential to support life, and a habitable exoplanet supports liquid water on its surface. However, a planet's success in maintaining liquid water on its surface is the end result of a complex…
Habitability is usually defined as the requirement for a terrestrial planet's atmosphere to sustain liquid water. This definition can be complemented by the dynamical requirement that other planets in the system do not gravitationally…