Is mankind or the sun responsible for climate change?

Is mankind or the sun responsible for climate change? Is the earth getting hotter or colder? These are some of the key points to be debated at an international conference next week at the Hebrew University of Jerusalem.

The conference, 'Solar, Cosmic Rays and Climate Connections', is being coordinated by the Institute for Advanced Studies and the National Science Foundation.

According to one of the conference organizers, Prof. Nir Shaviv of the Racah Institute of Physics at the Hebrew University, the goal of the conference is to discuss and debate the relative climatic role played by the sun.

“Although it is an interesting question by itself, it has ramifications to the understanding of present and future climate change. If the sun is an important climate driver, some of the 20th century warming should be attributed to the sun – implying that the human role is smaller and with it the expected warming over the 21st century.”

However, some of the participants in the conference – among them, Prof. Juerg Beer of the EAWAG Research Institute in Switzerland – claim that the sun doesn't have such an impact on the climate and that global warming is influenced more by the actions of mankind. According to this hypothesis, the warming of the earth will continue in the 21st century at a rate of up to 0.2 degrees per decade.

Some of the issues to be discussed by the speakers from Israel, India, Canada, Germany, Denmark, Finland, Britain and Switzerland include: How large is the solar climate link and is it amplified? Is the climate very sensitive? Can we prove or rule out cosmic rays? Can we determine the mechanism(s) for a CR climate link? Do we find a relationship between cosmic rays and climate in the past? Weather influence on the Earth wheat markets: Past, present and future.

The conference will take place Sunday, April 25 – Thursday, April 29, at the Feldman Building, Edmond J. Safra campus.