BBC NEWS | Science/Nature | 'No Sun link' to climate change - The Diigo Meta page

• 01 Feb 13
  

  steph1223
  • changes in cosmic rays coming to Earth determine cloudiness and temperature.
  • variations in solar activity affect cosmic ray intensity.
  • scientists found there has been no significant link between cosmic rays and cloudiness in the last 20 years.
  • Presenting their findings in the Institute of Physics journal, Environmental Research Letters, the University of Lancaster team explain that they used three different ways to search for a correlation, and found virtually none.
  • Cosmic rays are deflected away from Earth by our planet's magnetic field, and by the solar wind - streams of electrically charged particles coming from the Sun.

  • The Svensmark hypothesis is that when the solar wind is weak, more cosmic rays penetrate to Earth. 

    That creates more charged particles in the atmosphere, which in turn induces more clouds to form, cooling the climate. 

    The planet warms up when the Sun's output is strong.
  • But another researcher who has worked on the issue, Giles Harrison from Reading University, said the work was important "as it provides an upper limit on the cosmic ray-cloud effect in global satellite cloud data".
  • cosmic rays make only a very weak contribution to cloud formation.
  • solar activity has been slowly declining, which should have led to a drop in global temperatures if the theory was correct.

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• 23 Nov 12
  

  climate climatechange globalwarming science environment carbon solar sun

• 21 Sep 08
  

  Manny C

  climate_change cloud solar_activity temperatures

• 17 Apr 08
  

  Kawthar Muhaib

  Scientists have produced further compelling evidence showing that modern-day climate change is not caused by changes in the Sun's activity

  ClimateChange Environment Politics

• 03 Apr 08
  

  Gert Gast

  science

• 

  julien dossier

  During one of the Sun's 11-year cycles, there was a weak correlation between cosmic ray intensity and cloud cover (which could at the very most explain only a quarter of the changes in cloudiness). And for the following cycle, no correlation was found

  solar research source environment carbon

• 

  Duane Raymond

  news articles climatechange science

• 

  Aldo de Moor

  global_warming

• 

  Peng Yonggang
  • Scientists have produced further compelling evidence showing that modern-day climate change is not caused by changes in the Sun's activity.
  • The research contradicts a favoured theory of climate "sceptics", that changes in cosmic rays coming to Earth determine cloudiness and temperature.
  • The idea is that variations in solar activity affect cosmic ray intensity.
  • Presenting their findings in the Institute of Physics journal, Environmental Research Letters, the UK team explain that they used three different ways to search for a correlation, and found virtually none.
  • The IPCC has got it right, so we had better carry on trying to cut carbon emissions
  • at the very least
  • Dr Svensmark's idea formed a centrepiece of the controversial documentary The Great Global Warming Swindle.
  • If he is right, then we are going down the wrong path of taking all these expensive measures to cut carbon emissions; if he is right, we could carry on with carbon emissions as normal.
  • streams of electrically charged particles coming from the Sun.
  • The Svensmark hypothesis is that when the solar wind is weak, more cosmic rays penetrate to Earth.
  • Professor Sloan's team investigated the link by looking for periods in time and for places on the Earth which had documented weak or strong cosmic ray arrivals, and seeing if that affected the cloudiness observed in those locations or at those times.
  • So we looked to see whether cloud cover increased after one of these bursts of rays from the Sun
  • Over the course of one of the Sun's natural 11-year cycles, there was a weak correlation between cosmic ray intensity and cloud cover - but cosmic ray variability could at the very most explain only a quarter of the changes in cloudiness.
  • This work is important as it provides an upper limit on the cosmic ray-cloud effect in global satellite cloud data
  • Dr Giles Harrison from Reading University, a leading researcher in the physics of clouds
  • The Svensmark hypothesis has also been attacked in recent months by Mike Lockwood from the UK's Rutherford-Appleton Laboratory.
  • He showed that over the last 20 years, solar activity has been rising, which should have led to a drop in global temperatures if the theory was correct.
  • Intergovernmental Panel on Climate Change (IPCC)
  • since temperatures began rising rapidly in the 1970s, the contribution of humankind's greenhouse gas emissions has outweighed that of the Sun by a factor of about 13 to one.
  • We tried to corroborate Svensmark's hypothesis, but we could not; as far as we can see, he has no reason to challenge the IPCC - the IPCC has got it right

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