Chapter 15, An Alternative Hypothesis, describes Dr. Svensmark's
hypothesis on cosmic rays.
Not exact matches
The galactic
cosmic ray (GCR) warming
hypothesis is based
on the premise that GCRs can «seed» clouds, and clouds reflect sunilight.
On the possibility of a changing cloud cover «forcing» global warming in recent times (assuming we can just ignore the CO2 physics and current literature on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the cosmic ray hypothesi
On the possibility of a changing cloud cover «forcing» global warming in recent times (assuming we can just ignore the CO2 physics and current literature
on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the cosmic ray hypothesi
on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the
cosmic ray hypothesis.
Correlations such as the
cosmic -
ray / cloud
hypothesis are based
on, are merely suggestive of such physics (although they may simply reflect a joint correlation to a third independent factor).
There have been many studies aiming to test this
hypothesis since AR4, 50 which fall in two categories: i) studies that seek to establish a causal relationship between
cosmic rays and 51 aerosols / clouds by looking at correlations between the two quantities
on timescales of days to decades, and 52 ii) studies that test through observations or modelling one of the physical mechanisms that have been put 53 forward.
There have been many studies aiming to test this
hypothesis since AR4, which fall in two categories: i) studies that seek to establish a causal relationship between
cosmic rays and aerosols / clouds by looking at correlations between the two quantities
on timescales of days to decades, and studies that test through observations or modeling one of the physical mechanisms that have been put forward.
Dear Nir Shaviv, I would be glad to receive your comment about the recent paper from Andrew C. Overholt et al 2009 ApJ 705 L101 - L103 doi: 10.1088 / 0004 - 637X / 705 / 2 / L101 TESTING THE LINK BETWEEN TERRESTRIAL CLIMATE CHANGE AND GALA Does it mean - the spiral arm mechanism you suggest does nt fit - can some other mechanism explain your measurements and
hypothesis - does this have an impact
on the
cosmic ray climate theory or not If we talk about the paradox of the faint young sun, imho its still an issue that any mechanism solving the problem of the major ice ages occuring each 140 million years in the last billion, does nt work for the first 3 billion years.
The CLOUD project at the European Center for Nuclear Research is probing the Svensmark - Shaviv
hypothesis on the role of
cosmic rays modulated by the solar magnetic field
on the low cloud coverage; the first and encouraging results have been published in Nature.
The galactic
cosmic ray (GCR) warming
hypothesis is based
on the premise that GCRs can «seed» clouds, and clouds reflect sunilight.