Q & A
Nobel Laureate Proposes an Equation for Optimism
By Diego Cevallos
Scientist Mario Molina predicts that in 10 years the Mexican capital, one of the most polluted cities in the world, could have very clean air.
MEXICO CITY, (Tierramérica).- Air quality, climate change and the ozone layer are variables in an equation that humans have been toying with, to the extent of endangering our very future, Mexican scientist Mario Molina, 1995 winner of the Nobel Prize for Chemistry, said in a conversation with Tierramérica.
But there are reasons for optimism, says Molina, who after achieving fame for discovering that chlorofluorocarbons (CFCs) damage the Earth's stratospheric ozone layer, has worked on a program to improve air quality in Mexico City.
He argues that in around 10 years, the Mexican capital, today one of the most polluted megacities in the world, could have ''very clean'' air.
The scientist says his prediction could come true if there is commitment and effort -- elements he believes played a key role in the ''success'' of the 1987 Montreal Protocol, in which the international community accepted the challenge to halt the destruction of the ozone layer. Despite alarmist reports, says Molina, there is no going back on the road towards the recovery of the ozone layer.
Q: Scientists from Cambridge University expressed alarm in April at the European Union's meeting on geophysics, held in Austria, because according to their studies the thinning of the ozone layer had reached its maximum. They talk about continued destruction. Is it true? If so, what has gone wrong?
A: Year to year, there is great variability in the so-called ozone hole, as there is in many other climate-related areas. The hole is not expanding in a continuous way, and it is clear that the emissions of industrial compounds that hurt the ozone layer are diminishing. The problem has basically been resolved through the Montreal Protocol (which set timelines for reducing the use of CFCs and other ozone-depleting substances), although we have to continue to work hard, because there are substances like methyl bromide that have not yet been totally eliminated, as is the case of some halons, which are still being emitted. We know we have to wait approximately two decades before the ozone layer begins to recover, and from one year to the next the thinning could increase or decrease without that being an important indication of the status of the problem, which the Montreal Protocol has dealt with irreversibly and effectively.
Q: The temporary widening of the hole, then, is related to the phenomenon of climate change (global warming as a result of emissions of ''greenhouse'' gases)?
A: One of the things that make it difficult to say with precision when the stratospheric ozone layer will be restored is the connection between this problem and the fact that we are altering the climate (with greenhouse gas emissions). It is possible that this recovery will be delayed because climate change affects it, in a way that is difficult to understand, but is real.
Q: In that relationship, does air quality -- an area that you're working in now -- play a role?
A: Yes, there are important connections between ozone, climate change and air quality. They are elements of a delicate equation. What we are doing in Mexico City is attack the air quality problem, and some of the measures also are beneficial in relation to climate change. For example, improving the efficiency of transportation reduces emissions of carbon dioxide, which is the leading greenhouse gas, but also emission of other substances that affect air quality and human health.
Q: You have recommended changes in the formula of the gasoline consumed in Mexico, modernization of vehicles and an overhaul of the public transportation system, among other measures. Will they solve the problem of intense air pollution?
A: That's it. If there is an effort and commitment, in around 10 years Mexico City will have very clean air. That prediction might sound overly optimistic, when there are so many connected problems too, but it can be done and there are examples that confirm this, like the U.S. city of Los Angeles. In these matters, and in others related to climate change, Latin America and the developing world have not yet adopted very clear measures, but the experience of Mexico will be a good example of what can be done.
Q: What is your view for the future when there are countries like the United States that resist adopting strong commitments for fighting climate change?
A: It is a difficult and risky future. There are very big challenges, and the use of fossil fuels is linked to economic development. That is why close collaboration between industrialized and developing countries is essential, in part because it is the former that have polluted the air. As for the United States, I think that country's individual states and researchers are making great efforts to attack the problems of ozone depletion, climate change and air quality, but the current government (of President George W. Bush) is opposed to anything that involves international commitments, which is a shame.
* Diego Cevallos is an IPS correspondent.