The Chilling Stars A new theory of climate change Henrik Svensmark, Center for Sun Climate Research Danish National Space Center Basel, Marts2007

Variations in Cosmic Ray Flux Affects Earths Climate, and Cause Variations in Climate. Cosmic Rays and Climate Examples with Solar Modulated Cosmic rays CLIMATE COSMIC RAYS

What are Cosmic Rays? Heliosphere, Cosmic Rays and Solar Activity

Coronal Mass Ejections (CME) One month of observation Movie

Cosmic ray shower (Movie) About 70 muons/s /m 2 at the Earths surface In 24 hours about 12 million muons goes through a human body

Cosmic Rays in a Cloud Chamber (movie)

Cosmic rays and climate over the last millennium

8 Cosmic rays and climate over the last years Bond et al, Science 294, 2001 Last 1000 years Little Ice Age Little Ice Age is merely the most recent of a dozen such events during the last years

How can STARS influence Climate?

Possible physical mechanism Mechanism that amplifies tiny GCR energy input

Svensmark & Friis-Christensen, JASTP 1997, Svensmark, PRL 1998, Marsh & Svensmark, PRL, (update 2005) Link between Low Cloud Cover and Galactic Cosmic Rays?

Micro-physical Mechanism? CLOUDS CLIMATE COSMIC RAYS Experimental Studies at DNSC in Copenhagen

Cloud Drop CCN (Cloud Condensation Nuclei) CN (Condensation Nuclei) UCN (Ultra Fine Condensation Nuclei) 0.1  m 10  m0.01  m0.001  m Aerosol formation and growth Size H 2 SO 4 & Water & Organic Vapors Possible link between clouds and cosmic rays Nucleation process has been a mystery

Cloud Drop CCN (Cloud Condensation Nuclei) CN (Condensation Nuclei) UCN (Ultra Fine Condensation Nuclei) 0.1  m 10  m0.01  m0.001  m Aerosol formation and growth Size H 2 SO 4 & Water Vapors What is the importance of IONS ? - + Cosmic Ray Ionization &

Gamma source Muon detector Radon detector SO 2 O 3 H 2 O

Steady state experiment q (cm -3 s -1 ) H 2 SO 4 concentration ~ 2*10 8 (cm -3 ) O 3 ~ 25 ppb SO 2 ~ 300 ppt RH ~ 35% Svensmark et al. PRA 2006

Äspö Hard Rock Laboratoriet, Sweden Hopefully an experiment will take place with near zero ionization in spring m Next experiment Surface 70 /s/m m 0.7 /s/m2 200 m 0.07 /s/m2 However radon is a concern - lead shield ( How to stop cosmic rays)

Hard Rock Laboratory, Aspø Sweden ~ 500 meter of rock

Micro-physical Mechanism? CLOUDS CLIMATE COSMIC RAYS GALACTIC PROCESSES Micro-physical Mechanism?

The Milky Way, Super Novae and Cosmic Rays Starformation, Super Novae and Cosmic Rays

The Milky Way, Super Novae and Cosmic Rays

Birdseye view of Milkyway Svensmark A&G 2007

Cosmic rays and spiral arm crossing Shaviv, PRL (2002) Million of Years Estimated Cosmic Ray Flux

Svensmark A&G 2007

What about longer time scales, i.e over the history of the Earth 4.6 Billion years? Although Cosmic ray fluxes are not known so far back in time, they can be constructed from knowledge of 1.Solar Evolution 2.History of Star Formation Rate in the Milky Way

Insight to the evolution of our Sun is gained from extensive studies of solar proxies with ages from 100 Myr to 10 Gyr Solar Evolution Pressure balance Heliopause The young Sun was rotating at a rate at least 10 times faster than today. As a consequence, 1) The Sun had a vigorous magnetic activity 2) Coronal X-ray and EUV emissions up to 1000 times stronger than today. 3) The Sun had a denser solar wind A better shilding of Cosmic rays

Solar Evolution, Star Rate Formation and Cosmic Rays Svensmark, Astronomical Notes 2006 Starformation, Super Novae and Cosmic Rays

Solar Evolution, Star Rate Formation and Cosmic Rays Svensmark, Astronomical Notes 2006 Starformation, Super Novae and Cosmic Rays

Formation and interaction between galaxies

Minor merger (dawfgalaxy) with spiral galaxy

Cosmic Rays and the Biosphere in 4 Billion Years 10 GeV C = 0.92 Svensmark, Astronomical Notes 2006 Starformation, Super Novae and Cosmic Rays

1.Variations in Star Formation Rate in the Milky Way and Solar Evolution Cause Variations in the Cosmic Ray Flux Impacting Earth. 2.Variations in Cosmic Ray Flux Cause Variations in Climate. 3.Variations in Climate Cause Variations in total Biological Productivity. The Argumentation is Based on the Following Assumptions About Cause and Effects Starformation, Super Novae and Cosmic Rays

If more carbon is stored in one of these reservoirs, the isotopic composition of others reservoirs changes to reflect that storage. For instance: if there is more carbon stored in organic matter which is isotopically light, the average carbon composition of dissolved carbon in the ocean and carbon dioxide in the atmosphere will become heavier. Carbon Isotopes The various reservoirs of carbon on Earth (limestone, biota and CO 2 in atmosphere) Starformation, Super Novae and Cosmic Rays

Svensmark, Astronomical Notes 2006 Carbon 13 during 3.8 billion years Standard deviation In steps of 400 mill yr Starformation, Super Novae and Cosmic Rays

Cosmic Rays and the Biosphere in 4 Billion Years 10 GeV C = 0.92 Svensmark, Astronomical Notes 2006 Starformation, Super Novae and Cosmic Rays

Hofman and Schrag point to cap carbonate abruptly above glaciomarine dropstone Snowball Earth

Cold Climate Equator Pole Ice Warm Cold Large temperature difference between equator and pole Strong winds – Mixing of Nutriants Large biological productivity Large fluctuations biological productivity possible Starformation, Super Novae and Cosmic Rays

Hot Climate Equator Pole Hot Warm Small temperature difference between equator and pole Weak winds – Little Mixing of Nutriants Small biological productivity Small fluctuations in biological productivity Starformation, Super Novae and Cosmic Rays

Conclusion Particles from space seems to influence Earths climate, ranging from years to 10 9 years. Part of the missing physical mechanism has been demonstrated experimentally Involving ions and aerosol formation Linking to clouds and thereby the energy budget of the Earth Understanding the cosmic ray climate link could have large implications in our understanding of climate changes and possible evolution on Earth. The evolution of the Milky Way and the Earth is linked It is not suggested that it is the only cause of climate change.

The team: Martin Enghoff Nigel D. Marsh Jens Olaf Pedersen Ulrik I. Uggerhøj Henrik Svensmark Center for Sun-Climate Research