NITROUS OXIDE EMISSIONS FROM THE ARABIAN SEA ..
Nitrous oxide emissions from the Arabian Sea: a synthesis.
This essay has presented Earth’s many changing faces during its journey. Earth had molten beginnings, was , and may have . Later, and and . Earth experienced swings from to conditions as atmospheric gases dramatically changed, continents moved, and vast and of complex life played out on land and sea. But the changes happened over timescales of millions and billions of years, not hundreds. No climate scientist will deny that carbon dioxide traps infrared radiation and warms Earth’s atmosphere. The vented enough carbon dioxide into the atmosphere to create 200 million years of Greenhouse Earth conditions, when reptiles ruled Earth. Volcanism waned and around 150-to-100 mya. By 35 mya, and the Antarctic ice sheet began forming. Every paleoclimate study I have seen places greenhouse gas (and primarily carbon dioxide) concentrations as the primary determinant of global surface temperatures, after the Sun's radiation, but the Sun's output is considered to have been exceptionally stable and has risen slowly over the eons. , usually by accentuating the carbon dioxide with a positive feedback effect that may have reached runaway conditions at times.
key factors on emissions of nitrous oxide in ..
In recent years, Neogene temperatures have been the focus of intensive research. What appears to be the proximate cause of elevated temperatures was a dramatic change in global ocean currents. The final closing of the , the isolation of Antarctica, the creation of , and the opening and closing of land bridges, such as in the Bering Sea and ultimately the land bridge between North and South America, created dramatic changes in ocean currents and global climate. One result was fluctuating . Its production declined beginning about 24 mya, and its weakness lasted until about 14 mya. Consequently, Earth’s oceans were not stratified as they are today, and warm water extended far lower into the oceans than it does today. Also, it reduced the temperature gradient between the equator and poles, which drives global currents: the greater the differential, the more vigorous the currents. It was still an Icehouse Earth, but the “mid-Miocene climatic optimum” was relatively warm. The past three million years are the coldest that Earth has seen since the that ended 260 mya, but this . While the steadily declining carbon dioxide levels of the past 150-100 million years is the ultimate cause of this Icehouse Earth phase, relatively short-term and regional fluctuations have had their proximate causes rooted in other geophysical, geochemical, and celestial dynamics.