President's Corner

Earth exploration for science and society

"Understanding the complex, changing planet upon which we live, how it supports life and how it will support life in the future is one of the greatest intellectual challenges facing humanity."

-- Earth Science and Applications from Space: Urgent Needs and Opportunities to Serve the Nation,
National Research Council,
April 2005 (see "On the Web").

Imagine the excitement if we caught a glimpse of another planet in the universe that harbored life, no matter how simple. Then imagine that further observations suggested that this planet supported life and civilizations as rich, complex, and unknown as we can conceive. Our intense curiosity about this new planet and its life system, the social behaviors and cultures of its civilizations, how it developed, and where it was going in the future would inspire, challenge, and perhaps even frighten us as no discovery ever has before.

What will her planet be like when she is a grandmother? (Photo by Richard Anthes.)

In fact, we live on just such a planet, and what we don't know about it far exceeds what we do. The dictum that opens this article, from a recently released report by the National Research Council (see "On the Web") is one of the most important ones for our future. It leads to a profound question:  Is human life sustainable, and if so, what is the path to sustainability?  We can only begin to formulate possible answers to this question with the knowledge we now have.

Seeking knowledge about the past, present, and future of Earth is not merely an abstract quest for us to pursue, as if we were physically and emotionally detached beings in a faraway galaxy studying a very curious planet, wondering how it got here and what will happen to it. What happens to Earth will determine the future of our species.

And yet we also affect Earth's future. Our ability to influence the Earth system means that we are active participants in the changing Earth rather than passive observers. The human influences may be relatively minor and benign for some time, or they might suddenly trigger great perturbations to our natural support systems, with devastating impacts on our lives and civilization. We can speculate about the likelihood of these two extremes and an infinite number of scenarios in between, but the fact is we just don't know enough to say how Earth will evolve and how we must adjust to the inevitable changes.

In the 1980s, the U.S. and the international community realized that Earth could only be understood by considering it as a complex system connected through myriad physical, biological, and chemical processes, each one scientifically challenging by itself. Most importantly, the community recognized that these connections and dependencies extend to all life, including humans. To address this paradigm, NASA's Earth Observing System (EOS) began in 1991 as a presidential initiative to study Earth as a system.

This vision leads to a number of related questions:

  • How stable is the Earth system?
  • Why is it as stable as it is, given the constant minor and occasionally catastrophic perturbations?
  • How predictable or unpredictable is it?
  • How are humans changing it?
  • What will Earth look like 50 years from now (when today's first graders are running the world)?
  • What will it look like 200 years from now, when their great-grandchildren are raising their families?

There is plenty of evidence that these are more than rhetorical questions and that finding answers is important and urgent. While climate change has received most of the popular and political attention to Earth issues in recent years, there are other equally or perhaps more dangerous hints that not all is right with Earth's human support systems. In a recently released landmark study, the Millennium Ecosystem Assessment (see "On the Web"), 1,300 experts from around the world assembled research results from thousands of peer-reviewed studies in an attempt to assess the state of ecosystems across the entire planet. Rather than discuss individual events and threats such as zebra mussel invasions, deforestation, loss of arable land to wind and water, species extinction, and many others, they tried to put together all of these events in a global context. They focused on how these connected ecosystems over Earth support human life and civilization through their effects on water, food, fiber, shelter, natural hazards, invasive species, and infectious diseases.

An important conclusion of this assessment was that unpredictable abrupt changes might occur, analogous to the development of the ozone hole in the 1970s. Examples that we could face include the emergence of new and rapidly spreading diseases, creation of "dead zones" along the coasts, collapse of fisheries, and large changes in regional storm and rainfall patterns--all with enormous impacts on economies, human health, and quality of life.

The imperative for understanding Earth is strengthened by the fact that the intellectual endeavor is accompanied by many practical applications that produce societal benefits. In addition to the scientific challenge of understanding how Earth sustained or extinguished life in the past and the sustainability of life into the future, Earth system science provides the foundation for many beneficial societal applications that have been counted and recounted often in the past. Earth information, predictions, and warnings protect lives and property; support industries such as agriculture, transportation, construction, and the management of natural resources (food, fiber, water, and energy); make economies more efficient; support national security; and enhance the daily lives of all people.

"One of my main ensuring that the full range of science, including Earth science, remains a priority at NASA even as we move ahead to return to the moon by 2020. There is simply no planet more important to human beings than our own, and we're remarkably ignorant about it."

--Sherwood Boehlert, chair of the House Science Committee, speaking to the Consortium for Oceanographic Research and Education on 9 March, 2005.

We take these benefits for granted, not realizing that most of them began as ideas spawned from intellectual curiosity and the challenge of doing something never done before. With the support of observations, scientific analysis, and innovative technologies, these ideas led to understanding, which then provided the foundation upon which to build useful applications. The story of global weather prediction is an outstanding example (see sidebar).

Achieving, maintaining and enhancing these societal benefits are, sadly, viewed by some as rather mundane and ancillary consequences of incremental knowledge. But Earth sciences derives its greatest strength from twin objectives:  the increase of scientific knowledge and the application of that knowledge to achieve societal benefits.

Vigorous exploration of Earth through observations, analysis, and theory must continue, because history tells us that we cannot foresee very far into the future how Earth will change or how new discoveries will benefit society. For example, nobody foresaw the advent of weather radars and satellites and their applications--yet imagine how, without these observations and the warnings which were based upon them, the residents of Florida would have coped with the four hurricanes of 2004.

Continuing the exploration of Earth is not just about achieving incremental societal benefits, though these will certainly repay the modest financial investment many times over. The exploration is crucial to developing an understanding of this complex and ever-changing planet and its life---a tiny part of the universe, but the part most important to the future of humanity.

One of the unique characteristics of humans compared to other life forms is our ability to see the big picture, take a long-term view, understand how we fit into this complex world, how that world is changing around us, and prepare for the future. We are able to not only envision different futures for ourselves, our children, and their children, but also to consciously and deliberately influence the future. Other species go extinct without ever knowing it, much less understanding why they were becoming extinct or being able to do anything about it. Though occupying important niches in the planet's web of life, they live their lives ignorant of their place in the world and oblivious to threats beyond the most immediate and local ones. Their interests are confined to their narrow environment and are overwhelmingly dominated by immediate needs--food, shelter, security, and reproduction. They are unaware of their collective past and that the continued existence of their species is not guaranteed. And even if glimmers of insight into these questions were present, they would not have the intellectual and technological capability to observe their planet as a whole, to devote some of their energies toward understanding it, and most of all to ensure that it remained a hospitable home for their children and their children's children.

We humans, on the other hand, are fully aware that our continued existence is not guaranteed. We are capable of knowing and learning from the past and comprehending and determining the future. We have the intelligence, resources, and capabilities to understand our world and our place in it. If we go extinct, we will be aware of it, we will know why, and we will bear some of the responsibility for it.



A tale of progress

One of the greatest scientific achievements and societal benefits provided by Earth sciences in the past 30 years has been the steady improvements of global weather forecasts. This figure shows the moving monthly average of the correlation (a perfect forecast would be 100%) between observed and forecast weather features at 500 millibars (the approximate midpoint of the atmosphere) for 3-, 5-, and 7-day forecasts made by the European Centre for Medium-Range Weather Forecasts (ECMWF).

Figure courtesy Tony Hollingsworth, ECMWF, and is updated from the figure published by A. J. Simmons and A. Hollingsworth, "Some aspects of the improvement in skill of numerical weather prediction," Quarterly Journal of the Royal Meteorological Society 128 (2002), 647-678.

The accuracy of these forecasts of mid-atmospheric flows--upon which accurate forecasts of hurricanes, floods, droughts, and other significant weather features depend--has been increasing steadily since 1980.

This dramatic improvement is due to better understanding of the atmosphere-Earth system, more and better global satellite observations, and improved numerical models that assimilate the many observations.

The forecast improvements are especially dramatic across the Southern Hemisphere (bottom line of each colored band), a sign that the benefits of advanced satellite data are available equitably to both North and South. Recent work has shown that we are not yet near the end of possible improvements.


Also in this issue:

Examining the N factor

Big year in 2007: IPY & IGY

Firor-Jacobsen Fellowship

Blue Gene: Small but powerful

President's Corner

HIAPER arrives

New directors for SERE, ISSE

Faculty Fellowship Program

Community Calendar