Susan Leschine ~ Full interview

Professor in microbiology at the University of Massachusetts

1.  What are the most urgent problems in the field of climate change in your view?

I feel that the links between fossil fuel combustion, climate change and global warming are compelling. We urgently must limit greenhouse gas emissions. This becomes more and more evident with each new report; for example, a report in the Proceedings of the National Academy of Sciences in the US that carbon dioxide emissions are growing more rapidly than anticipated and the ability of the land and oceans to absorb carbon dioxide from the atmosphere has diminished. This is the most urgent problem.

Also, from the point of view of energy security in different states and countries, reducing dependence on fossil fuel is an important issue. Oil drives the economy in the US. Political decisions are often based on our thirst for oil.

2.  And what kind of solutions do you see for these problems?

For limiting greenhouse gas emission the most obvious and immediate solution is limiting emissions due to transportation, domestic use and industry. We must also find alternatives to burning fossil carbon (coal and oil) and we need to develop renewable, sustainable sources of energy.

I am specifically involved in developing alternative transportation fuels to reduce the use of fossil fuels for transportation. The only form of energy that can contribute substantially to fulfilling transportation fuel requirements at costs competitive with fossil fuels is solar energy captured by plants and stored as biomass. At present, plant biomass is the only significant source of liquid transportation fuel that may replace the world’s finite supply of oil.

3.  Do you think we can use solar energy directly?

Yes, for generating electricity. But currently solar electricity is expensive and will require improvements to bring down costs. The technology for electric and hybrid cars is still being developed. As of now, electricity is not cost-effective for transportation. Our transportation infrastructure depends on liquid fuels.

At the moment getting to more sustainable liquid fuels for transportation is only possible by converting biomass into fuels.

4.  In your opinion, what is the best way to convert biomass into biofuel?

This is an area where we are still developing the technologies. At present, most of the biomass that is converted into transportation fuel is plant material that has other uses. This becomes especially problematic when the other use is food. Currently in the US biomass comes from corn. However, we are developing new technologies that make use of the whole plant, especially the parts that are now considered to be waste. The development of cellulosic ethanol as transportation fuel is my specific interest. This is the direction we should take, I think.

There are many potentially good technologies. We have not yet identified which are best. To be economically viable, they still need governmental subsidies and assistance of various sorts. Therefore, we should examine all alternatives. I focus on a biological conversion process using microbes to convert biomass into fuel. But there are also chemical conversion processes. We need to explore all opportunities until it becomes clear which technologies will be cost effective in each particular situation, depending on the biomass input.

5.  What do you think are the necessary conditions for these techniques to be successful?

The advancement of effective new technologies requires resources. Much of the development is still at the basic research level. To develop biomass fuels, cellulosic ethanol specifically, will require additional resources. In a more general sense, I think a necessary condition for realizing success is the general recognition by the public of the overall problem of global warming and the need for solutions. This is necessary in order to make the required investments politically acceptable. Scientists can play a role here: we must explain our work to the public. We need to find the right solutions, politically acceptable and environmentally friendly solutions.

6.  Do you think biotechnology can contribute to the solutions or techniques you mentioned?

Absolutely. The development of biofuels certainly could involve biotechnology. As I mentioned, there are two biomass conversion methods, chemical and biological. Biological conversion uses microbes and enzymes to convert biomass to ethanol. Basically, this is biotechnology.

7.  Is there a difference between the techniques of biotechnology?

Interesting question, because for the general public, biotechnology often is synonymous with genetic modification. But the field of biotechnology is much broader and does not necessarily involve recombinant genetic techniques. To give you an example: the technology I am working on with SunEthanol is based on a microbial fermentation of biomass. And one of the ways in which we can advance the technology and improve it is by doing something called ‘adaptive evolution’. This means that we grow microbial cultures on a particular form of biomass, and we select the microbes that grow the fastest. We use processes that occur naturally in bacteria and select those with the improved properties. You can use this technique to identify genes that change over time, to better understand the cell metabolic processes. There are many forms of biotechnology that we could use. Sometimes we use techniques of DNA manipulation, but use of these techniques does not automatically mean we end up with recombinant organisms or GMOs.

8.  Will this lead to more public debate?

I am sure it will. But the debate should focus on the science. There is no evidence that the use of biotechnology is necessarily detrimental, and there are ample examples of beneficial outcomes. I believe that we must focus on how biotechnology is used, rather than whether or not it is inherently bad.

9.  Can you tell us if there are differences between developing and developed countries?

It is clear and obvious that there are enormous differences among developed and developing countries. Both the problems and the solutions will vary depending on particular circumstances. And the solutions will depend on the resources available. For example, Brazil is almost independent of imported oil. This was helped by a decision made years ago to focus on cane ethanol. Now Brazil is a leader in biomass ethanol production. Approaches have varied enormously from country to country. Impacts of global warming will vary among countries and the ability of a country to absorb these impacts will vary. In general, developed countries have more resources to overcome some of the impacts of global warming than developing countries have.

10.  But if you look at, for instance, the debate about fuel and food maybe you can elaborate more on that debate?

This is a very important and serious issue. Certainly, we should work to avoid using food to make transportation fuel. It is obvious that this issue should be examined on a global scale. We need to come up with global solutions such as cellulosic ethanol and biomass products that do not use food crops. This will happen in time.

But at the moment we are using food crops for ethanol production and this is being debated in the media. For instance, the news media lavished considerable attention on a recent US report, which concluded that corn ethanol has already impacted land use change. There were many criticisms to this report, but the news media did not cover the subtleties of the issue. The news media have an obligation to follow the science thoroughly and accurately. If they do not, there are negative consequences for society.

It is essential that we move to non-food sources of biomass as soon as possible. Although corn ethanol is not perfect, it represents an improvement over burning petroleum. I believe we cannot give up on such solutions because they are not perfect. We need to look at them as stepping stones to better solutions.

11.  What will the field of climate change look like in 20 years time?

In 20 years time, to be optimistic, although global warming effects will be worse than today, we will be on a path to controlling greenhouse gas emissions.

12.  Do you have any other remarks that you like to add to this subject?

I would like to mention a grassroots educational initiative in the US called ‘Focus the Nation’. It does show that in the US there are people who think about the problems and propose solutions. The initiative proposes a ‘2% solution’ meaning a 2% decrease in greenhouse gas emissions for the next 40 years. This initiative puts global warming in perspective first of all. It helps to focus our nation on the issue and suggests solutions. It’s encouraging.

Furthermore, we must recognize the need for major lifestyle changes to reduce global warming, and we need to develop new technologies to address climate change and to find renewable and sustainable sources of energy.

13.  Are there any initiatives in the US that promote a lifestyle with less energy use?

At the state level there are various tax incentives for renewable energy. But there is no coherent policy. California has been quite successful in initial attempts to control the use of resources through the policies of Governor Schwarzenegger.

14.  Do you have a statement, question or dilemma for the website?

What will it take to reach a global consensus on the severity of the impact of climate change in order to develop the political will to find real solutions?