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Dire outlook despite global warming 'pause': study

A global warming "pause" over the past decade may invalidate the harshest climate change predictions for the next 50 to 100 years, a study said Sunday—though levels remain in the danger zone.

Space & Earth - Environment

May 19, 2013

3.8 / 5 (37)

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Researchers reveal model of Sun's magnetic field

Researchers at the Universities of Leeds and Chicago have uncovered an important mechanism behind the generation of astrophysical magnetic fields such as that of the Sun.

Space & Earth - Astronomy

May 22, 2013

4.4 / 5 (7)

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Error sought & found: State-of-the-art measurement technique optimised

A systematic error has been eliminated from a measurement technique for analysing the physical properties of the Earth's atmosphere using signals from GPS satellites – thanks to an Austrian Science Fund ...

Physics - General Physics

May 23, 2013

5 / 5 (1)

0

Climate change and wildfire: Synthesis of recent findings

Concerns continue to grow about the effects of climate change on fire. Wildfires are expected to increase 50 percent across the United States under a changing climate, over 100 percent in areas of the West by 2050 as projected ...

Space & Earth - Environment

May 21, 2013

5 / 5 (3)

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Solar variation

Solar variations are changes in the amount of solar radiation emitted by the Sun. There are periodic components to these variations, the principal one being the 11-year solar cycle (or sunspot cycle), as well as aperiodic fluctuations. Solar activity has been measured via satellites during recent decades and through 'proxy' variables in prior times. Climate scientists are interested in understanding what, if any, effect variations in solar activity have on the Earth. Effects on the earth caused by solar activity are called "solar forcing".

The variations in total solar irradiance remained at or below the threshold of detectability until the satellite era, although the small fraction in ultra-violet wavelengths varies by a few percent. Total solar output is now measured to vary (over the last three 11-year sunspot cycles) by approximately 0.1% or about 1.3 W/m² peak-to-trough during the 11 year sunspot cycle. The amount of solar radiation received at the outer surface of Earth's atmosphere averages 1,366 watts per square meter (W/m²). There are no direct measurements of the longer-term variation and interpretations of proxy measures of variations differ. On the low side North et al. report results suggesting ~ 0.1% variation over the last 2,000 years. Others suggest the change has been ~ 0.2% increase in solar irradiance just since the 17th century. The combination of solar variation and volcanic effects are likely to have contributed to climate change, for example during the Maunder Minimum. Apart from solar brightness variations, more subtle solar magnetic activity influences on climate from cosmic rays or the Sun's ultraviolet radiation cannot be excluded although confirmation is not at hand since physical models for such effects are still too poorly developed.

This text uses material from Wikipedia, licensed under CC BY-SA

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