Our Changing Planet and Its Microbiome David M. Karl Council on Foreign Relations Roundtable 9 June 2014  Washington, D.C.

OUTLINE Evolution of life and the human imprint Honor thy microbe and its genome! The changing planet – IPCC A sustainable future?

“Thus human beings are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future” Tellus (1957) IGY Brochure (1957)

THE KEELING CURVE

INTRODUCTION TO SEA MICROBES

Microbes have a long history on Earth, especially compared to man

DIVERSITY Phylogenetic Metabolic Habitat/Niche Space TIME is a critical variable for all three properties

MARINE MICROORGANISMS Control production and consumption of organic matter/oxygen, and poise pH/redox Production and consumption of “greenhouse” gases (CO 2, CH 4, N 2 O) Control N availability: N 2 fixation, nitrification and denitrification Contain enormous genomic potential that sustains metabolic flexibility Microbes make things happen!

THE SECOND “GOLDEN AGE” OF MICROBIOLOGY: THE –OMICS ERA YearDiscoveryDiscoverer 1988Prochlorococcus – the most abundant photosynthetic microbe in the sea Chisholm et al. 1990SAR-11 clade – the most abundant microbe in the seaGiovannoni et al. 1992Planktonic Archaea – the third domain of life (along with bacteria and eukaryotes) DeLong/Fuhrman 2000Aerobic anoxygenic phototrophy – a novel, specialized type of solar energy capture Kolber et al. 2000Proteorhodopsin phototrophy – a novel, ubiquitous type of solar energy capture DeLong/Béjà 2001Picoplanktonic N 2 fixers – a novel component of the oceanic nitrogen cycle Zehr et al Full genome sequences of marine microbes – novel organisms with new genes, new proteins, and new metabolic processes many

J.C. Venter et al. (2004) “Environmental shotgun sequencing of the Sargasso Sea” Science 304: Sargasso Sea (200 l), shotgun sequencing approach – Few thousand new species – More than 1,000,000 new protein-coding genes (10x the total # discovered to date) – Hundreds of new photoreceptors that may capture energy from sunlight Surface seawater only!

Science, society and sustainability are inextricably linked! The “Larger Context”

Created in 1988 – just 26 years ago World Meteorological Organization (WMO) and United Nations Environmental Program (UNEP) Mission: “To provide governments of the world with a clear scientific view of the world’s climate” Intergovernmental Panel on Climate Change (IPCC)

AR-1 (1990): Baseline for state of the planet AR-4 (2007): AR-5 ( ) IPCC Assessment Reports “Warming in the climate system is unequivocal” “The ocean is changing”

Assessment Findings are classified using relative terms and quantitative probability statements: Virtually certain99-100% probability Very likely90-100% probability Likely66-100% probability About as likely as not33-66% probability Unlikely0-33% probability Extremely unlikely0-10% probability Exceptionally unlikely0-1% probability

IPCC AR5-WGII-Chapter 6

Warming and enhanced stratification: circulation, productivity Acidification and loss of oxygen: impacts metabolism and growth Biodiversity losses and invasions: changing distribution, abundances and reproduction patterns Coastal erosion and pollution: eutrophication, dead zones CHANGING OCEAN ECOSYSTEMS

“In the absence of time-series data sets, contemporary field observations are hidden in the ‘invisible present’” John Magnuson 1990 Bioscience 40: 495 A “call to arms” for ocean time-series

Global and transdisciplinary C-N-P cycles Process studies, time-series, data assimilation and modeling Hypothesis generation and testing Education and training JGOFS est. 1984

established October 1988

Air-sea carbon cycle processes Acidification

ACID, CO 2 AND MICROBES More observations and experiments are needed

Conceptual understanding of the sea, Earth’s largest biome Global productivity and other ecosystem services Ocean carbon sequestration and climate Planetary habitability and human survival WHAT IS AT STAKE? quite a bit!

NOT EVEN THE TIP OF THE ICEBERG! T. Newberger Microbial oceanography: new opportunities New microbes, novel physiology/biochemistry New paradigms regarding energy flow in the sea The 2 nd Golden Age of Microbiology …living in the invisible present

“Ocean science can no longer be viewed as an esoteric, ‘offshore’ discipline. It is mainland and mainstream. The health and bounty of our oceans are issues of planetary survival.” NSF Director Rita Colwell at NRC Symposium on Fifty Years of Ocean Discovery 30 October 1998