Post-Publication: The Future of Z. Li’s Ten-Year Aerosol Study

It’s been three months since Zhanqing Li and his team released their groundbreaking study on air pollution, and they’re still feeling the effects.

Sitting in his corner office at ESSIC, Li excitedly Googles the terms “Li,” “pollution,” and “precipitation,” and sits back as the screen regurgitates millions of related links. Almost all of them are tied to his study, and as he scrolls down the page his own name flashes in front of him over and over again. The same search in Chinese yields almost as many results.

It’s a result than any scientist would hope for, and one certainly worthy of the work Li put in to his study over the past ten years.

This past November, he published the results of a study that showed the first clear long-term effects of aerosols on weather and climate. Over the past ten years, Li and a team of scientists have been measuring how small particles in the atmosphere like dirt or soot can create changes in precipitation.

While it has been known that aerosols in the atmosphere can affect precipitation and cloud formations in the short term, the effects have never been observed in the long term, said Li.

“The aerosol climate impact has been in our community interest for many, many years but it was the net impact, or overall impact, that has been lacking, which is the most important one,” he said.

The study focused on data gathered from the U.S. Southern Great Plains research facility in Oklahoma, and while other studies have been conducted in other areas, Li says that the UMD-led study was the most robust because of the use of both ground data and global satellite data.

With thousands of citations now featuring Li’s paper, it’s easy to discover the in-depth results of the study. But in a simple sentence: it precipitates less in dry areas and more in wet regions or seasons when the air is dirty.

With high amounts of aerosols suspended in the air, the mean cloud height of deep convective clouds doubles, along with the probability of heavy rain in wet areas or less rain in the dry ones. But what does this actually mean?

It’s the “so what” that Li, like so many scientists, is after.

“As a scientist our goal is to try and dig deeper in to the problem and find the truth,” said Li. “But of course, as scientists we hope to help the environment and the people.”

The results from the study may be able to do just that. With many developing nations susceptible to weather extremes, studying the impacts on precipitation formation can help to curb severities like floods or droughts.

But it isn’t up to the scientists to both discover and fix the problems, said Li.

“Our goal is not so much the policy because we are not the policy maker, so that’s up to the public,” said Li. “This is just the first step.”

Still, he has high hopes for lawmakers, even if the changes are slow.

“Policy change is going to be subtle, but there will be public pressure given what our findings are, especially in places like India, China, Brazil…it will be built up because of this study,” Li said.

It’s a study, says Li, that anyone can grasp.

“This is really easy for the public to understand: ruining the climate means ruining the environment, which means ruining the economy.”

Since Li and his team published the study, the global response to this concept has been enormous. In a recent trip to China, despite traveling for research unrelated to his current study, there was still huge press interest everywhere, said Li. Meanwhile, he’s been answering heavy volumes of e-mails from journalists from around the world, some of which are written in languages he doesn’t even know.

In the aftermath of his study’s success, Li continues to plan his next steps. His next move will be to not only continue to communicate globally, but to collect global data as well.

“Right now we’re trying to investigate individual cases and in particular we want to know if this phenomenon could happen anywhere in the world,” he said.

Li and his team have all the fundamental data, he said, in the sense that they have the most dramatic results for both favorable conditions and least favorable conditions, but are lacking in data from the medium regions.

“We need to study different variable conditions, and identify the different regions and different kinds of clouds that are sensitive,” said Li.

He is currently involved in work with climate modelers, and hopes to be able to create a large scale model for aerosol effects that can then be used globally. The challenge, he said, is to simulate all of the different conditions in the world.

So, despite the latest breakthrough results, Li is already looking to the future. Scanning through the Google results page, his pride in the study is obvious, but his work is far from over.

“Right now we are just opening the door,” he said. “There are definitely a lot more studies needed.”

(Related: See ESSIC News Highlight on study publication.)