The Chilling Stars A new theory of climate

The Chilling Stars A new theory of climate change Henrik Svensmark, Center for Sun Climate Research Danish National Space Center Basel, Marts 2007

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

Cosmic rays and climate over the last 10. 000 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 8 the last 10. 000 years

How can STARS influence Climate?

Possible physical mechanism • Mechanism that amplifies tiny GCR energy input

Link between Low Cloud Cover and Galactic Cosmic Rays? Svensmark & Friis-Christensen, JASTP 1997, Svensmark, PRL 1998, Marsh & Svensmark, PRL, 2000. (update 2005)

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

Aerosol formation and growth Possible link between clouds and cosmic rays H 2 SO 4 & Water & Organic Vapors CN Cloud Drop (Condensation Nuclei) UCN CCN (Ultra Fine Condensation Nuclei) (Cloud Condensation Nuclei) Size 0. 001 mm Nucleation process has been a mystery 0. 01 mm 0. 1 mm 10 mm

Cosmic Ray Ionization & Aerosol formation and growth + H 2 SO 4 & Water CN - Cloud Drop (Condensation Nuclei) Vapors UCN CCN (Ultra Fine Condensation Nuclei) (Cloud Condensation Nuclei) Size 0. 001 mm What is the importance of IONS ? 0. 01 mm 0. 1 mm 10 mm

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

Steady state experiment q (cm-3 s-1) 0 10 20 30 40 50 60 H 2 SO 4 concentration ~ 2*108 (cm-3) O 3 ~ 25 ppb SO 2 ~ 300 ppt RH ~ 35% Svensmark et al. PRA 2006

Next experiment ( How to stop cosmic rays) 500 m Äspö Hard Rock Laboratoriet, Sweden Surface 70 /s/m 2 100 m 0. 7 /s/m 2 200 m 0. 07 /s/m 2 However radon is a concern - lead shield Hopefully an experiment will take place with near zero ionization in spring 2007

Hard Rock Laboratory, Aspø Sweden ~ 500 meter of rock

CLOUDS COSMIC RAYS Micro-physical Mechanism? GALACTIC PROCESSES CLIMATE

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

The Milky Way, Super Novae and Cosmic Rays

Birdseye view of Milkyway Svensmark A&G 2007

0 0. 5 1 1. 5 600 200 400 Million of Years Estimated Cosmic Ray Flux Cosmic rays and spiral arm crossing 0 Shaviv, PRL (2002)

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

Solar Evolution Insight to the evolution of our Sun is gained from extensive studies of solar proxies with ages from 100 Myr to 10 Gyr 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 Pressure balance Heliopause

Starformation, Super Novae and 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

Formation and interaction between galaxies

Minor merger (dawfgalaxy) with spiral galaxy

Starformation, Super Novae and Cosmic Rays and the Biosphere in 4 Billion Years C = 0. 92 10 Ge. V Svensmark, Astronomical Notes 2006

Starformation, Super Novae and Cosmic Rays The Argumentation is Based on the Following Assumptions About Cause and Effects 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.

Starformation, Super Novae and Cosmic Rays Carbon Isotopes The various reservoirs of carbon on Earth (limestone, biota and CO 2 in atmosphere) 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.

Starformation, Super Novae and Cosmic Rays Carbon 13 during 3. 8 billion years Standard deviation In steps of 400 mill yr Svensmark, Astronomical Notes 2006

Starformation, Super Novae and Cosmic Rays and the Biosphere in 4 Billion Years C = 0. 92 10 Ge. V Svensmark, Astronomical Notes 2006

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

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

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

Conclusion Particles from space seems to influence Earths climate, ranging from years to 109 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