IPCC Conclude - It is likely that the presently observed global warming is man made Most geologists – we have seen it all before, the Earth has gone through warm and cold periods in the past The paleoclimatology was nicely described this morning by Jasper Kirkby NB during the last several hundred thousand years the CO2 level in the atmosphere never was more than 300 ppm. It was It was 280 ppm in 1850 and it as risen since to 380 ppm since and is still rising. The climatologists think that this is the source of global warming. But – what part is played cosmic rays ? Up to the present cosmic rays have been ignored as insignificant by the IPCC. How much of the radiative forcing could be caused by cosmic rays.

Conclusions Contribution of cosmic rays to global warming varies from 100% to 0% depending on who you ask – need for more research – eloquently advocated by E Flückiger this morning. There are huge uncertainties - many people are confident they know the answers – need more data and research on this topic which is in its infancy.

Correlation of cosmic rays with the weather By weather we mean short term changes By climate we mean long term changes Possibly there is a correlation with hurricanes (Kavlakov) (with Kp index but Forbush descreases more doubtful) No correlation with rain at Moussala – posters 1.21 and 1.27 (but some reported in earlier papers – Stozhkov 2002 Veretenko and Pudovkin 1994).

How much Radiative Forcing could come from cosmic rays ? Compared to estimated ~2 W m -2 expected from CO 2 Depends who you ask

Svensmark et al - ALL OF IT Y. Stozhkov – poster 1.11 it is not a problem – the temperature behaves cyclically and it will come down again – also cometary dust plays a part. Cyclic behaviour modelled by Fourier analysis. My worry – CO2 is not cyclic – man made part is projected to Increase. Voiculescu et al – some of it –elegant attempt to correlate UVI and CR with LCC - AWW log N->log S plot seems to show correlation is stronger with UVI than with CR – need to understand the significance of this statistical analysis. Various other reports in the past of correlations between cloudiness and CR (Harrison et al., Veretenko and Pudovkin, Stozhkov et al). Rusov et al Energy Balance model explains it all and predicts global cooling TS, Erlykin and Wolfendale < 23% of dip in LCC in solar cycle 22 is caused by cosmic rays. Arnold – utterly negligible.

Experimental data now becoming available CLOUD and SKY. Crucial to do more experiments.