Daily Archives: April 29, 2013

Study: Earth’s cooling ended in 1900

 

A reconstruction of 2,000 years of global temperatures shows that a long-term decline in Earth’s temperatures ended abruptly about 1900, replaced by a warming trend that has continued despite the persistence into the 20th century of the factors driving the cooling, according to a new study. 

Indeed, for several continents, the increase in global average temperatures from the 19th century to the 20th was the highest century-to-century increase during the 2,000-year span, the study indicates. It’s the first study to attempt building a millennial-scale climate history, continent by continent. 

The research wasn’t designed to identify the cause of the warming trend, which climate researchers say has been triggered by a buildup of greenhouse gases – mainly carbon dioxide – as humans burned increasing amounts of fossil fuel and altered the landscape in ways that released CO2. 

Still, it’s hard to explain 20th-century warming without including the influence of rising CO2 levels, because the factors driving the cooling were still present, notes Darrell Kaufman, a researcher at Northern Arizona University and one of the lead authors on the paper formally reporting the results in the journal Nature Geoscience. 

The study, five years in the making, drew on the work of 87 scientists in 24 countries as part of the International Geosphere-Biosphere Program. One goal of the 27-year-old program is to gain a deeper understanding of Earth’s climate history and the factors that contribute to climate variability. 

The study used nature’s proxies for thermometers – tree rings, pollen, and other natural temperature indicators – to build continent by continent a coordinated record of temperature changes during the past two millenniums. 
Scientists use this proxy approach to reach further into the climate’s temperature history than the relatively short thermometer record allows. Such efforts aim to put today’s climate into a deeper historical context as well as to identify the duration and possible triggers for natural swings that the climate undergoes over a variety of time scales. (Source: Christian Science Monitor)

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What Tax Preparation Software Looked Like in 1991

 

What Tax Preparation Software Looked Like in 1991.

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Why does water swirls clockwise and anticlockwise in different parts of the world.

Why does water going down a plughole spin in one direction in the Northern hemisphere and in the other direction in the Southern? Which way (if any) does it spin on the equator? Also are there any planets which don’t spin?

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It doesn’t. This often asked question is an “urban myth” that derives from a misapplication of the physics phenomenon known as the Coriolis Effect.The Coriolis effect derives from the rotation of the Earth, and does effect a number of important physical systems. Winds blow clockwise around high pressure systems in the northern hemisphere and counterclocwise around high pressure systems in the southern hemisphere as a result of the Coriolis Effect, and the motion of ocean currents are affected by the rotation. However, water going down drains, toilets, or sinks is not effected by the rotation of the earth, rather, the motion of water in such small basins is determined by the friction between the basin and the water, the shape of the basin, and other such factors, but not by the rotation of the earth.

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