Related papers: Nitrous Oxide and Climate
Despite a fainter Sun, the surface of the early Earth was mostly ice-free. Proposed solutions to this so-called "faint young Sun problem" have usually involved higher amounts of greenhouse gases than present in the modern-day atmosphere.…
Observations show that the lower thermosphere of Mars ($\sim$100--140 km) is up to 40 K colder than the current general circulation models (GCMs) can reproduce. Possible candidates for physical processes missing in the models are larger…
A climate response function is introduced that consists of six exponential (low-pass) filters with weights depending as a power law on their e-folding times. The response of this two-parameter function to the combined forcings of solar…
Context: The thermal and chemical structures of the upper atmospheres of planets crucially influence losses to space and must be understood to constrain the effects of losses on atmospheric evolution. Aims: We develop a 1D first-principles…
What transpires from recent research is that temperatures and radiative forcing seem to be characterized by a linear trend with two changes in the rate of growth. The first occurs in the early 60s and indicates a very large increase in the…
Planets orbiting in the habitable zone (HZ) of M-Dwarf stars are subject to high levels of galactic cosmic rays (GCRs) which produce nitrogen oxides in earthlike atmospheres. We investigate to what extent this NOx may modify biomarker…
Climate change is an important current issue and there is much debate about the causes and effects. This article examines the changes in our climate, comparing the recent changes with those in the past. There have been changes in…
Chemical and physical Earth models agree little as to the radioactive power of the planet. Each predicts a range of radioactive powers, overlapping slightly with the other at about 24 TW, and together spanning 14-46 TW. Approximately 20 %…
A review of some of the evidence for the IPCC's conclusion that doubling CO$_2$ levels will warm Earth significantly, in contrast to the claims of a recent article$^1$. Simply looking at raw temperature and CO$_2$ data over the past 150…
The glaciological record of atmospheric composition suggests O2 has declined over the last 800000 years at an average rate of 0.3 x 1012 mol (Tmol) O2 yr-1. Because the geological carbon cycle regulates long term atmospheric oxygen…
Abundant geomorphological and geochemical evidence of liquid water on the surface of early Mars during the late Noachian and early Hesperian periods needs to be reconciled with a fainter young Sun. While a dense CO2 atmosphere and related…
On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations…
The growing concentrations of the greenhouse gases CO2, CH4 and N2O (GHG) in the atmosphere are often considered as the dominant cause for the global warming during the past decades. The reported temperature data however do not display a…
We compute the ozone distribution for a model terrestrial paleoatmosphere in which the present oxygen abundance is largely replaced by carbon dioxide, which we argue is a reasonable working assumption. In principle, the presence of carbon…
We use a three-dimensional model to calculate steady-state climates at various intervals in Earth's future, across a parameter space of increasing insolation and decreasing CO$_2$ mixing ratio. Comparison with prior results shows an…
The amount of nitrogen in the atmosphere, oceans, crust, and mantle have important ramifications for Earth's biologic and geologic history. Despite this importance, the history and cycling of nitrogen in the Earth system is poorly…
Air pollution is a major driver of climate change. Anthropogenic emissions from the burning of fossil fuels for transportation and power generation emit large amounts of problematic air pollutants, including Greenhouse Gases (GHGs). Despite…
A model is proposed to explain the observed correlation between monthly fluctuations in atmospheric CO2 concentrations and temperatures. The model relies on the oceans being in a temperature-dependent equilibrium with the atmosphere. When…
The ratio of nitrogen isotopes in the Martian atmosphere is a key constraint on the planet's atmospheric evolution. However, enrichment of the heavy isotope expected due to atmospheric loss from sputtering and photochemical processes is…
The provision of accurate methods for predicting the climate response to anthropogenic and natural forcings is a key contemporary scientific challenge. Using a simplified and efficient open-source general circulation model of the atmosphere…