SCIENTIFIC OCEAN DRILLING AND EARTH'S CLIMATE HISTORY: PAST, PRESENT, AND FUTURE

Last year we celebrated an important milestone in the history of science—namely the 50^th anniversary of scientific ocean drilling in search of Earth’s secrets. A program that began in the United States with a small group of scientists, quickly grew through the power of its mission to encompass thousands of scientists on every continent, representing a vast swath of scientific disciplines including geophysics, geochemistry, marine biology, marine geology, micropaleontology and more. The extraordinary way in which the program evolved, from the Deep Sea Drilling Program, to the Ocean Drilling Program, to the Integrated Ocean Drilling Program, to the current International Ocean Discovery Program is a testament to the passionate global community of scientists who continually challenge themselves, and the program, to identify the most compelling and important scientific questions our “tool”, the drill ships, can tackle. I feel fortunate to have had a career where the drilling programs have been central to my science as well as to my growth as a scientist.

The 50-year history of the drilling programs is a history of connections—between people, countries, disciplines, ideas, hypotheses, the past, the present, and the future. Over this period and through the cores collected at sea we’ve gained a comprehensive understanding of why Earth’s climate changes naturally over geologic time—information that critically informs current discussions about on-going climate warming. Likewise, the discovery of numerous “tipping points” within the climate system, be they wholesale reorganizations of ocean circulation (the bipolar seesaw), ice sheet dynamics (D-O events), or even the global carbon cycle (the PETM) should give pause not just to scientists, but to all of us in Earth’s human family as we continue to pump powerful greenhouse gases into the atmosphere.

Finally, of all the challenges posed by Earth’s rapidly changing climate, one threat stands out—that of globally rising sea levels that threaten to displace up to a billion people by the end of this century. It was IODP drilling that demonstrated that sea level can rise at rates in excess of meters per century, a possibility we now face again. We know the ice sheets will collapse catastrophically if pushed for long enough by a slow, steady warming. The geologic record tells us it is imperative that we transition rapidly away from a fossil fuel-based economy.