CLIMATE CHANGE

LINK to my article at GLOBAL WARMING ARTICLES site:

APOCALYPSE AND BUTTERFLY EFFECT

Humanity has come a long way grasping the message since three scientists wrote the controversial book "Limits to Growth" in 1972, alerting us that resources of the earth are not infinite. Its 30-year update had a stronger warning that many resource and pollution levels had "overshot" beyond their "sustainable" limits; it foresaw disruption of economic systems if growth rates did not slow down. Today, as more nations seek consumption-based development, we continue to gobble up resources and pollute at ever increasing rates. And nature's distress signals get louder. But, rather than accepting them as omens of doom, we must take the opportunity to build sustainable economies.

When the first sign of a global "overshoot" came in late 70's unexpectedly from the stratosphere, the world organized quickly. Montreal Protocol progressively banned ozone-depleting substances and the ozone hole over the Antarctic is now expected to heal by 2050. Meanwhile, nearby Australia is the world's skin-cancer capital.

Global warming is another, grimmer, sign of an "overshoot." Greenhouse gas (GHG) emissions, from our stacks to exhaust pipes, far exceed the earth's capacity to absorb and they are changing the climate. Likely shifts in precipitation patterns and hence crop yields, disappearing snowcaps, rising sea levels… make regional catastrophes seem inevitable. We are urged to reduce emissions sharply and quickly. This is not an easy task but the Kyoto Protocol already took a first step forward.

Climate predictions are based on modeling studies and, surely, modeling the climate is complicated. It has "chaotic" features (inherently unpredictable); most of its components have "non-linear" relationships (not proportional); has mechanisms that work with "delays" (if carbon dioxide emissions stop, atmospheric concentration will continue to rise for a while), or positive "feedbacks" (warming tundra releases GHG, causing more warming, in turn causing further release); and its suspected "thresholds" of "abrupt change" scare scientists (local sea warming beyond a point may stop the ocean current).

Moreover, our time scale is minuscule compared to geological time. The earth had been in and out of ice ages over millions of years; we are interested in decades or centuries. There are other forces affecting the earth's climate such as variations in the earth's axis, or in sun's magnetic activity, tectonic movements, volcanism... Since the industrial revolution, GHG's appear to have outweighed them all. Their unprecedented levels for the last 800 thousand years indicate that we may be upsetting some balances; temperature hike within the last decades is alarming. However, we don't exactly know how much of these gases will continue to be absorbed, how much warming the excess will cause, or the responses of other mechanisms.

To incorporate unknowns into models, we make assumptions, and run them on super-computers to make projections in time and space. These models are far from being flawless and even their basic assumptions are challenged. Yet, they reflect the level of scientific knowledge today, and they succeed in reproducing the present conditions from past data. It would be too risky to wait beyond possible "thresholds" of no return.

On the other hand, going so far as to predict an apocalypse would neither be scientific, nor productive. Rather than predicting future events at "points" in time, long-term models project "behavior" of systems and help policy decisions by allowing comparison of alternative scenarios. "Short-term models" can make "point" predictions a few periods ahead. However, climate forecasts even for the near future are problematic. Let's remember the term "butterfly effect," used for fragility of chaotic systems, comes from meteorological models. (Can the flap of a butterfly in Brazil start/stop a tornado in Texas?)

Climate of the earth will continue to change. We can control the human impact. From scientists to musicians, industrialists to mothers… we must work with confidence to revamp our economies. This suggests changes in life-styles but successful local examples exist from Denmark to China. All we need is political will.

The monetary cost of transformation will not be nominal. But, for global warming, the recent Stern Review, prepared for the British Treasury, estimates that benefits of acting early far outweigh its cost on economies. And, as Lester Brown points out, by diverting only a portion of the billions dollars spent annually to promote GHG emitting activities (such as gasoline subsidies) we could be on course.

With worldwide cooperation and use of renewable technologies, our civilization can certainly overcome this and the yet-unforeseen challenges, while still managing to improve the quality of our lives. And us individuals shall continue to "flap our wings" to help avert the tempest.

Nukhet Barlas 2007

APOCALYPSE SOON?

(Summarized from my article in Cumhuriyet Science & Technology Magazine, April 13, 2007)

(Summarized from my article in Cumhuriyet Science & Technology Magazine, April 13, 2007)

APOCALYPSE SOON?

Humanity is faced with a great challenge. Because of changing climate, regional disasters seem inevitable. But, rather than accepting this as an omen of doom, we must take it as a sign of our exceeding the limits of earth's resources. We can take charge and stop the harm.

LIMITS OF RESOURCES

In 1972 three scientists predicted global crises if consumption rates of resources continued at increasing rates (Limits to Growth, Meadows et al). The 30-year update of their research had a grimmer conclusion that many resource and pollution levels had already "overshot" beyond their sustainable limits. But humanity had options to prevent disruption. (Meadows, 2004) Other subsequent studies calculated that resources (such as water and lumber) were being used high above their sustainable capacities. Today, we continue to gobble up resources and pollute at ever increasing rates as crowded nations develop under consumption-based economies. China already consumes more than USA. India will follow. It is obvious that a new economic model is needed (Lester Brown, Plan B2, 2006)

EXCEEDING THE LIMITS

When the first sign of a global "overshoot" came in the late 70's unexpectedly from the stratosphere, the world organized quickly. With the Montreal Protocol, ozone-depleting substances were progressively banned and the ozone hole over the Antarctic is expected to heal by 2050. Meanwhile, nearby Australia is the world's skin-cancer capital.

Global warming should be seen as a grimmer sign of another overshoot. We are releasing more greenhouse gases (GHG) than earth systems can absorb and hence, causing global warming with potentially devastating consequences. We are urged to reduce GHG emissions sharply. This is not an easy task and requires cooperation of reluctant nations. But, Kyoto Protocol already took a first step forward.

PREDICTION MODELS AND CLIMATE

Two types of models are used in future predictions: Short-term models that use past data to project few periods ahead, or long-term models that simulate long-term behavior of systems. In fact, rather than making predictions at time points, "long-term models" are used as aids in policy decisions by allowing comparison of the outcomes of alternative scenarios. "Short-term models" can predict a few periods ahead. However, climate forecasts even for near future are problematic. Let's remember that the term "butterfly effect," used for fragility of chaotic/complex systems, comes from meteorological models. (Can the flap of a butterfly in Brazil create or stop a tornado in Texas?)

IPCC report is based on modeling studies and, surely, modeling the climate is complicated. It has "chaotic" processes (inherently unpredictable); some of its components have "non-linear" relationships (not one-to-one); has mechanisms that work with "delays" (if carbon dioxide emissions stop, its atmospheric concentration will continue to increase for a while), or positive "feedbacks' (warming tundra's release GHG's, that causes more warming, in turn causing more GHG release); and its suspected "thresholds" of "abrupt change" scare scientists (local sea warming beyond a point may change the circulation in whole ocean).

In addition, the time frame we are concerned with is too short to make meaningful comparisons within geological time. The earth had been in and out of ice ages in millions of years; we are interested in decades or centuries. There are other (under-researched) forces affecting the earth's climate (such as variations in earth's axis and orbit, or in sun's magnetic activity, tectonic movements, volcanism…); since the industrial revolution, GHG's appear to have outweighed them all. Their unprecedented levels in the last 800 thousand years imply we are upsetting some balances and temperature hike within the last decades is alarming. But, we don't exactly know how much of the GHG's will continue to be absorbed, how much warming the excess will cause, or the responses of other mechanisms.

To incorporate all these into models, we make assumptions and run them on super-computers to make projections in time and space. These models are far from being flawless and even their basic assumptions are challenged. Yet, they reflect the level of scientific knowledge and practice today, and they succeed in regenerating the present from past data. Because it is too risky to wait beyond possible "thresholds" of no return, it is prudent to follow its recommendations. But, beyond that, predicting apocalypse is neither scientific nor productive.

SOLUTION

Climate of the earth will continue to change. What we can do is to control the human impact. Stronger measures to reduce GHG emissions are already being evaluated under Kyoto protocol and changing public opinion has already started to change the worst-case scenarios of the IPCC report. But, from a broader perspective, to be able to live in accord with the critical boundaries of our planet, we must revamp our economies to transform into "sustainable" societies. These suggest great changes in our life-styles but successful examples from Denmark to China exist already.

The monetary cost of change will not be nominal. But, the recent Stern Review (prepared for the British Treasury) estimates that benefits of acting early far outweigh the impacts of global warming on economies. And, as Lester Brown points out, renewable technologies would escalate with only a portion of the billions dollars spent every year to promote GHG emitting activities (such as gasoline subsidies).

With cooperation of nations and sectors of economies, our civilization can certainly overcome this and yet unforeseen challenges, while still managing to improve the quality of our lives. And us individuals, by fulfilling our share of responsibility, we will continue to look into the future with hope and optimism, our children and grandchildren as well.

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