Estimating methane from livestock (LOE)

Close to the end of my internship with Living on Earth, I worked on a short story which I got to narrate myself. Not only was I excited about my voice being carried on a Public Radio International show, I also got to say “poop” on the radio. I doubt that will ever happen again.

The story describes a study by researchers from the University of Bristol and the Teagasc Animal and Grassland Research Centre in Ireland. According to the study, quantities of a compound, archaeol, in cow dung, is directly proportionate to the amount of methane released by the animal. If such is the case, then climate scientists will no longer have to rely on rough estimates for methane from livestock.

CLICK HERE to listen to the story.

Do you remember the ozone debate?

Climate change is recurring feature in every news story, science book, and political debate; and a complicated environmental issue with strong economic and political factors. Almost every reference to this environmental phenomenon is linked with doomsday prophesy. But perhaps now is the time to look back at the late twentieth century when the countries of the world cooperated and addressed the biggest environmental problem of the time- the hole in the ozone layer.

The ozone hole is an important environmental lesson, for it clearly demonstrates the successful collaboration between public policy and science. Identified in the 1970s, the ozone hole over Antarctica created a stir in the scientific world, but now studies have shown that the ozone layer is on its way to a speedy recovery. By 2080, according to most estimates, the ozone will be restored to its levels in 1950. This is proof enough to show that with universal collaboration, strong leadership and public momentum, we can successfully deal with environmental issues, even complex ones like climate change. We saved the world from a catastrophe once and we have it in our power to do it again.

Like climate change, the ozone-hole issue was backed by a growing body of scientific evidence.   Situated about 30km above the Earth’s surface, the layer is responsible for keeping out the sun’s ultraviolet rays which are known to cause skin cancer and cataracts. In the 1970s scientists predicted a thinning of the ozone due to the accumulation of Chlorofluorocarbons (CFCs) in the atmosphere. CFCs are industrial compounds which were used widely in a variety of commercial and household applications. These synthetic compounds combined with oxygen molecules in the ozone layer resulting in fewer ozone molecules. The British Antarctic Survey discovered a huge hole over Antarctica in 1985, which rang alarm bells. The evidence was stark and the scientific solution was simple, and readily available. CFCs were phased out within a decade and replaced by Hydrofluorocarbons (HFCs).  “There was very little wiggle room left for nay-sayers,” says James Anderson, Professor of Atmospheric Chemistry at Harvard University. Unlike the climate-change debate today there were few skeptics who could deny the existence or causes of the formation of the ozone hole. The countries of the world pledged to phase out CFCs and signed the Montreal Protocol of 1987 making it the first universally ratified environmental treaty.

In some ways the climate change issue is similar to the ozone hole- both involve atmospheric change that require resolute global action. But they also have differences. Unlike the ozone hole, climate change is a polarizing, issue with skeptics questioning almost every claim that scientists raise. Some skeptics disagree with the very concept, stating instead that the planet is undergoing a predictable cyclical change. Others agree that these changes exist but disagree with the solutions provided. Furthermore there is massive disparity in the source of the problems. The ozone was damaged by a synthetic compound, and was replaced by another synthetic compound produced by the same manufacturer- DuPont. The industry made a switch and did not lose business. In contrast, carbon dioxide is a natural compound  linked to a trillion dollar energy industry. Oil and coal companies have not dealt with it in the same way as CFC manufacturers. “Rather than adapt they have chosen to deny,” said David Downie, Director, Programme on the Environment at Fairfield University. It’s time for these industries to learn from their forbearers and make the switch to cleaner, alternative sources of energy.

Internationally, climate change creates animosity among countries. The Intergovernmental Panel on Climate Change (IPCC) suggested that CO2 levels need to be reverted to 1920 levels in order to reverse environmental damage. The IPCC rulings have led to policy battles between developed countries and the developing world over  what their respective emission levels should be.  Caught up in protecting their own economies, countries have resisted ratifying the Kyoto Protocol. “People need to understand that the costs of impacts outweigh the costs of mitigation and adaption,” said David Downie, from Fairfield University, “but some countries just don’t have the money for either.”

The ozone layer issue shows us the importance of strong leadership in establishing a science-policy interface. NASA’s Robert Watson was the singular driving force behind the success of the Montreal Protocol. Under his leadership, science was introduced into public policy in an undisputed and rational manner. But today, things are different. “Scientists have a disproportionate and undervalued role,” said David Fahey from National Oceanic and Atmospheric Administration (NOAA), “we are reluctant participants.”We do know that the ozone hole was a localized issue, as opposed to climate change, and NASA had unique access to the stratosphere. However, it is worthwhile to note the successful role of Robert Watson, a singular scientific force at the federal level.  Science needs to marry public policy at a national and global level in order to reverse the effects of global warming. We need scientists with political powers to make a difference.

The ozone layer was not repaired by scientists and policy makers alone; public support was an invaluable component. People devoured scientific information on the negative health impacts of ultraviolet rays and initiated public campaigns to stay away from products using CFC compounds. Ad campaigns instilled the fear of skin cancer. Today, the public has failed to establish the relationship between extreme weather events and global climate change. Industries have misled the public with lies about climate change science. “Certain oil companies have given huge amounts of money to think tanks to write down the findings of the IPCC,” said David Downie. Stating the need for an ozone-hole equivalent for climate change, Stuart Gaffin states there has been no bullet-proof event which can prove climate change. The ozone hole was easier to identify with. “Everyone sits out in their backyard,” says Daniel Bader from the Climate Impacts Group at Columbia University, “people only respond to things when it affects them directly.”

There is no question that climate change is a much larger and complex issue than the ozone hole. Scientists have referred to the ozone-hole issue as ‘child’s play’ in the light of environmental problems today. Even if all carbon emissions were immediately dropped to ‘ideal’ levels, results would still be delayed. Studies suggest that the Earth’s temperature will continue to rise before it starts to drop. And this process could take centuries. Meanwhile, policy makers cannot come to a consensus on ideal emission levels. The situation is bleak and science is fighting a losing battle against economics.

Yet in spite of, or perhaps because of that complexity, now is the time to recognize that the planet is dynamic and not beyond recovery. Using the ozone issue as a successful prototype, we should   remember that collaborative action is possible. We need to put an end to our political strife and direct global economies towards investing in cleaner fuel sources.  This is no easy solution but it’s definitely possible. Industry needs to provide more options to address the planet’s growing energy needs. We need to strive harder to create a strong science-policy interface. There is hope for our planet and it lies in cooperation between governments and people.




  • Stuart Gaffin- Senior Researcher, Climate Impacts Group, Columbia University
  • David Bader- Research Analyst, Center for Climate Systems Research, Columbia University Earth Institute
  • Adam Greely- Research Analyst, Center for Climate Systems Research, Columbia University Earth Institute
  • James Anderson- Professor of Atmospheric Chemistry, Harvard University
  • David Downie- Director, Programme on the Environment, Associate Professor of Politics, Fairfield University
  • Cynthia Rosenzweig- Senior Research Scientist, Climate Impacts Group, NASA Goddard Institute for Space Studies
  • Dr David Fahey- Atmospheric Scientist, NOAA








Zoonotic Diseases

Think Swine Flu, Avian Influenza, Hantavirus and Lyme Disease and what immediately pops into one’s mind are images of squalor, dirty, plague-infested rats, pig and tics and all the menacing pathogens they bring with them. Labeled as ‘zoonotic diseases’, they have grown in number and impact in the last decade affecting human populations across the globe. But can these diseases and their rapid growth in the last couple of years be blamed on the animals themselves?

WHO defines zoonoses as “diseases and infections that are naturally transmitted between vertebrate animals and humans. A zoonotic agent may be a bacterium, a virus, a fungus or other communicable disease agent. At least 61% of all human pathogens are zoonotic, and have represented 75% of all emerging pathogens during the past decade.” According to a study by the Washington Department of Health, nine new human pathogens have emerged from 2000-2010 of which six are zoonotic in nature.

While these figures may appear alarming, there are those whose expertise leaves them unperturbed. “I do not think that’s terribly surprising,” said Dr Aaron Bernstein from the Harvard School of Public Health. “Infectious diseases in humans have similar cousins in other animals. It’s a pool of disease-agents which are closely related to each other and can be closely transmitted.” Some scientists are still debating over the figures. Dr Walter J. Tabachnick, Director of the Florida Medical Entomology Laboratory, University of Florida, says that there is “no data” to prove an overall increase in zoonotic diseases. “Few like dengue have increased, but that’s just a personal opinion,” he adds.

Studies have proven several factors leading to the sharp increase in zoonotic and vector-borne diseases in the last few years. While most point towards climate change being the largest contributing factor, many experts have opposing opinions. A widely expressed opinion states that climate change can only affect vector-borne diseases i.e. diseases transferred by arthropods or insects, as they are cold-blooded hosts. Since zoonoses specifically relates to diseases transmitted between vertebrate animals and humans, the climate change argument fails to apply to the entire gamut of zoonotic diseases. However, some scientists argue that warmer temperatures are not good enough to even explain the increase in vector-borne diseases alone.  “In order to have something happen, a lot of factors contribute to it. Temperature alone cannot make a difference. Malaria epidemics have decreased over the last 100 years, but the earth’s temperature has gotten warmer,” argues Dr Aaron Bernstein. Echoing a similar thought Dr Tabachnick feels that most studies “glibly offer assurances.” He adds that “climate change will have an effect, just like any environmental factor, but no one can predict specific consequences with assurance.”

With globalization of food, growth of cities and populations and spread of industry, came the excessive desire to constantly meddle with the earth’s environment and to alter its face. “We are reconstructing nature and causing humans to come into contact with animals in new ways,” says Dr Bernstein. He supports his claim providing examples from the live and wild animal markets in China stating how animals which would normally coexist in nature would be brought together in constrained conditions. The deadly Severe Acute Respiratory Syndrome (SARS) virus which claimed hundreds of lives in 2003-2004 can trace its origins to civet cats, which were held captive to feed the exotic food market, in China. Butchers of these cats were the first to be infected with the SARS virus.

Like Dr Bernstein, most scientists believe that people are misled into believing that the issue is climate change. The main problem is the constant and repetitive transformation of ecosystems on a large scale which breaks down ecological barriers. The way people interact with their live stock, their hunting practices, and their dependence on the land for their needs and their interaction within their own communities all add to the development of an epidemic. Dr Kenneth Gage, Chief of the Flea-borne Disease Activity Unit of the Centre of Disease Control (CDC), said “vector-borne disease cycles are very complicated. Land-use patterns and human behavior vastly add to these systems.”

Alterations in land-use can be singled out for older zoonotic diseases too.  Some studies demonstrate a correlation between the growth of the Atlantic seafood fishing industry and the introduction of the HIV AIDS virus in Western Africa. Rapidly increasing industrial fishing practices in the 1950s brought the fish population down to 10 percent of its original catchment a decade later. This made coastal tribes of Western Africa turn to bush meat to supplement their protein intake. The virus, once inside the human genome, mutated and became the Human Immunodeficiency Virus which became globally pandemic, nested within its travelling human host. “Twenty years ago people would have laughed at this reasoning,” said Dr Bernstein.

Human behavior within different societies, sharing the same environment, can show contrasting results in the spread of zoonotic diseases. Hantavirus, a lung disorder spread by rodents, spread wildly in Mexico in 1993-94 but was hardly significant on the other side of the Rio Grande River in the state of Texas. Dr Gage from the CDC points out that most Americans stay indoors on hot evenings in the comfort of their air-conditioned homes, while Mexicans would go outside on their porches to cool off. “These little things are very important,” he added.

In the case of zoonotic diseases, the factors are several and the impact is always the result of their cumulative effect. Understanding them is extremely complex as it involves a host of organisms from the pathogen, to the host to the infected organism, as well as the mutations which occur in this process. Dr Donald Thea from Boston University’s School of Public Health states that “it’s hard to talk about zoonotic diseases generically as they are a complex heterogenous body of biological beings.” He specifies that each disease needs to be studied and understood locally taking into consideration the environment, animal and human populations, industrial development and climate of the area. Moreover, scientists commonly agree that there is a lack of understanding the specifics of any particular episystem and the complexity of the interacting environment on vector-pathogen-host interaction. Due to these complexities, scientists seem to falter in their predictions for the future of these diseases. Even those confident in their climate models are questioned by the rest of the scientific community. “Predicting the impact of climate change in the future is like trying to predict how the stock market will behave in three years based on the conditions and information we have today,” said Dr Tabachinick.

While uncertainty may taint the understanding of the future of these diseases, resolution can be found in simple steps like educating local and medical communities globally. Dr Gage from the CDC notes that 14 percent of all fatal plague cases in the US, in the last 30 years, have been due to delayed medical attention or misdiagnosis. He states that the CDC focuses most of its efforts on educating people on managing their pets, livestock and disposing garbage in their neighbourhoods. Awareness and surveillance is the key to controlling the outbreak and spread of these diseases. He adds that with Remote Sensing and satellite imagery, scientists have access to land use, precipitation and pollution figures across the world which could help determine the possible epidemics in certain regions. “Theoretically we could reach a point for predicting zoonoses,” he adds. “But these diseases are very hard to predict and penetrate, “ he concludes soon after.