Climate Change and Cholera?

“Thirty years ago, we were ridiculed to even say that the bacterium existed in the environment. But now it is in textbooks. The evidence is so overwhelming, it is understood.” Rita Colwell - University of Maryland cholera expert, and former director of the National Science Foundation

Cholera was originally thought to be a disease purely associated with poor sanitation but recent revolutionary understanding suggest that beyond poor sanitation, other factors such as the environment, hydrology, and weather patterns also come into play (Shah, 2011; Fernándeza et al., 2009)

There is scientific evidence showing a direct influence of inter-annual and inter-decadal climate variability on the epidemiology of vector-borne diseases (WHO, 2000). Climate change has been shown to enhance the spread of infectious diseases two key mechanisms, according to (Epstein, 2011):

1)Global warming expands the geographic conditions conducive to transmission of vector-borne diseases, and
2)Extreme events result in the proliferation of mosquito, water and rodent-borne diseases

A study carried out in Lusaka (Zambia) between 2003 and 2006 analyzed data from three cholera epidemics which occurred in a consecutive fashion. The researchers from the Madrid Carlos III Institute of Health who conducted the study concluded that climatic variables (rain and environmental temperature) are related to the increase in cholera cases during the epidemic period. The results showed that increase in environmental temperature six weeks before the rain season increases the number of people affected by this sickness by 4.9%.

In a study of Vibrio cholera, the bacteria that causes cholera, in the environment, the bacteria was found in water bodies untouched by human waste, its abundance and distribution fluctuating not with levels of contamination, but with sea surface temperature, ocean currents, and weather changes. A 2003 WHO study warned that predicted warming of African lakes, such as Lake Tanganyika, may increase the risk of cholera transmission among local people, and that countries such as Tanzania, Kenya, Guinea-Bissau, Chad, Somalia, Peru, Nicaragua, and Honduras — which suffered major cholera outbreaks after heavy rains in 1997 — may face more cholera epidemics as the climate changes (Shah 2011).

It seems the evidence is becoming so overwhelming. According to Shah (2011) “In Mexico, the abundance of cholera vibrios in lagoon oysters rise as seas warm. In the Chesapeake Bay, Vibrio cholerae levels increase during the summer, as water temperatures spike. In Bangladesh, cholera risk increases by two to four times in the six weeks following a 5-degree C (9-degree F) spike in the water temperature. Likewise, in Ghana, an analysis of 20 years of data revealed a correlation between cholera incidence and rainfall and land surface temperatures. In Djibouti, Somalia, Kenya, Mozambique, and Tanzania, cholera epidemics have been correlated with flooding as well as sea surface temperatures”

As the impacts of climate change on diseases become increasingly prominent, the need to put in place structures and mechanisms to ensure health care systems are well positioned to respond effectively cannot be over-emphasised. How can the health care system, especially in developing countries, respond appropriately to climate change related health risks?

"This is the first time that it has become evident in the sub-Saharan region that the increase in environmental temperature is related to the increase in cholera cases," - Miguel Ángel Luque, Madrid Carlos III Institute of Health

References:
Epstein, P., 2011. Health and Climate Change: 7 Ways You Are Being Harmed in The Atlantic, Sept. 23, 2011 Edition.

Fernándeza, M.A.L., Bauernfeindb, A., Jiménezc, J.D., Gila,C.L., El Omeiria, N., Dionisio Herrera Guiberte, D.H., 2009. Influence of temperature and rainfall on the evolution of cholera epidemics in Lusaka, Zambia, 2003–2006: analysis of a time series. Transactions of the Royal Society of Tropical Medicine and Hygiene. Volume 103, Issue 2. Pages 137–143

Government of Ghana, 2007. National Health Policy: Creating wealth through health. Ministry of Health. Accra, Ghana.

Shah, S., 2011. Climate’s Strong Fingerprint in Global Cholera Outbreaks. Environment360. http://e360.yale.edu/feature/climates_strong_fingerprint__in_global_cholera_outbreaks/2371/

World Health Organization Bulletin, 2000. Climate change and vector-borne diseases: a regional analysis. http://www.who.int/mediacentre/news/releases/2008/pr28/en/index.html [Accessed: June 19, 2012]

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GEOENGINEERING TO THE RESCUE?

“Homo sapiens has emerged as a force of nature rivaling climatic and geologic forces,” Erle Ellis

"Geo-engineering" as a solution to climate change is increasingly gaining attention within the science world. "Isn’t it just one of those things that come up and everyone seems excited about only to learn later that it can’t really help after all?”, I asked myself the first time I read about geoengineering. So what is this technology that is gradually becoming the main word in climate change talks?

The concept of GEOENGINEERING refers to "the deliberate large-scale intervention in the Earth’s climate system, in order to moderate global warming". The definition of geoengeneering in itself seemed ironic to me, upon first hearing. How can anyone possibly make any meaningful interventions in the climate system which is so complex that I am yet to come across someone who can claim to fully understand it! Then the Intergovernmental Panel on Climate Change concluded in 2007 that geoengineering options remained largely unproven. Such is the controversy surrounding geongeneering.

But why should anyone not be happy with what appears to have solution to arguable the greatest challenge the world faces: CLIMATE CHANGE. The world has been grappling with this challenge for a while now. Climate change MITIGATION, activities that reduce greenhouse gas (GHG) emissions, or enhance the capacity of carbon sinks to absorb GHGs from the atmosphere, has been proposed several years ago and we are still grappling with it. Climate Change ADAPTATION, i.e., reducing the negative impacts of climate change and take advantage of any opportunities is also being tried and its successes are there for all to see. It has been extremely difficult and sometimes even thought of as impossible to build the international political consensus on how and to what levels to reduce GHG emissions. Talk of adaptation is equally discouraging. So, with all these challenges with mitigation and adaptation, are we now closer to what will save the world?

Geoengeneering is divided into two broad categories:
1.Carbon dioxide removal (CDR) techniques which address the root cause of climate change by removing greenhouse gases from the atmosphere; and
2. Solar radiation management (SRM) techniques which attempt to offset effects of increased greenhouse gas concentrations by causing the Earth to absorb less solar radiation.

CDR techniques will reduce the levels of carbon dioxide (CO2) in the atmosphere, allowing outgoing long-wave (thermal infra-red) heat radiation to escape more easily. SRM techniques will reduce the net incoming short-wave (ultra-violet and visible) solar radiation received, by deflecting sunlight, or by increasing the reflectivity (albedo) of the atmosphere, clouds or the Earth’s surface. These are surely what the world needs to address climate change, don’t you think so? At last, we are going to win the battle with climate change! Well, don’t be too fast to conclude, does geoengineering not have any negatives?

Some of the few studies into geoengineering has revealed that despite all the positives, including counteracting many effects of climate change, that are touted about Geoengineering, there could be unintended negative repercussions as well. The climate system is inherently too complex and the possibility of unanticipated harmful side effects must be expected. In their book “GEOENGINEERING FOR DECISION MAKERS” the Woodrow Wilson International Center for Scholars, lists the ten (10) major concerns of Geoengineering as:
1.Unintended Negative Consequences
2.Potential Ineffectiveness
3.Risk of Undermining Emissions-Mitigation Efforts
4.Risk of Sudden Catastrophic Warming
5.Equity Issues
6.Difficulty of Reaching Agreement
7.Potential for Weaponization
8.Reduced Efficiency of Solar Energy
9.Danger of Corporate Interests Overriding the Public Interest
10.Danger of Research Driving Inappropriate Deployment

These concerns, some of which have been addressed partially by some studies, are important and need addressing before any large-scale deployment of geoengineering technologies is undertaken.

So is geoengenieering to the rescue? It’s time for us to think, work and engage. Maybe YES, maybe NO. What do you think?

"Before we start geoengineering we have to raise the following question: are we sufficiently talented to take on what might become the onerous permanent task of keeping the Earth in homeostasis? Consider what might happen if we start by using a stratospheric aerosol to ameliorate global heating; even if it succeeds, it would not be long before we face the additional problem of ocean acidification. -- James Lovelock

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CLIMATE CHANGE AND AGRICULTURE: ASSESSING AFRICA’S VULNERABILITY

The contribution of agriculture to GDP in Africa varies across countries but assessments suggest an average contribution of 21% (ranging from 10 to 70%) of GDP (Mendelsohn et al., 2000).

Introduction
The Inter-Governmental Panel on Climate Change (IPCC) defines vulnerability as “the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is a function of the character, magnitude, and rate of climate variation to which a system is exposed, its sensitivity, and its adaptive capacity.

In Africa, the agricultural sector contributes about 30% of the continent’s GDP and provides a source of livelihood for almost 70% of Africans (Climate Change and Agriculture in Africa). The agricultural sector has its own problems such as rapid urbanization pushing more fertile arable land out of production, competition with subsidized farmers in Western countries, low productivity of lands, use of obsolete equipment and many more. Compounding the problems of the African farmer is impacts of climate change; increased variability in rains, higher overall temperatures, and storm events that are more frequent and/or more intense. Due to the major role that agriculture plays in the economies of African countries, any slight negative impact on agriculture has significant effects on the people.

Projections of climate change impacts on Agriculture in Africa
Agriculture in Africa is climate-dependent, generally rainfed, and this makes the continent highly vulnerable to climate change. The Intergovernmental Panel on Climate Change (IPCC), projects:
•that 75-250 million people in Africa will face severe water stress by 2020 and 350-600 million people by 2050 due to climate change
•that Agricultural production in Africa will be severely compromised due to loss of land, shorter growing seasons, and more uncertainty about what and when to plant due to climate change
•a possible 50% reduction in yields from rain-fed crops by 2020 in some North African countries, and crop net revenues likely to fall by as much as 90% by 2100 in South Africa.

So, Africa is highly vulnerable to the effects of climate change and the impacts of climate change on African agriculture cannot be overemphasized. As climate change progresses at a faster rate, the vulnerability of Africa’s agriculture worsens.

The Approach for Vulnerability Assessment
Generally, Vulnerability of a system is a function of Exposure, Sensitivity and Adaptive Capacity, i.e.,
Vulnerability = f (Exposure, Sensitivity, Adaptive Capacity)

A vulnerability assessment must, therefore, answer these questions:
Who (or what) is vulnerable …………………………………… System
To what are they vulnerable …………………………………… Exposure
Why are they vulnerable …………………………………………… Sensitivity
What can be done to lessen this vulnerability …………… Adaptive capacity

It is so tempting, and usually the easy way out, to assess the vulnerability of Agriculture at the continental level but the impacts of climate change vary significantly due to the diversity of environments across Africa. So a general vulnerability assessment would usually leave out some hotspots due to the averaging of conditions which takes place at the continent-wide level vulnerability assessment. So as much as possible, it is advisable to lower the scale at which vulnerability assessments are done in order not to leave out specific situations that need addressing.

Importance of assessing Africa’s Agricultural vulnerability to decision makers
Assessing vulnerability is not only important for responding to future climate risks and also the process of assessment also brings out key answers needed to improve the management of current climate risks. A good vulnerability assessment will contribute to setting development priorities and monitoring progress.

Conclusion
First and foremost, for an effective Vulnerability Assessment, one needs to understand who and what is at risk. Understanding who and what is at risk is critical in deciding strategies and measures that may be taken to reduce risk or increase capacity to adapt. An appropriate vulnerability assessment method is very important because each the method or approach one chooses may end up giving a whole different view of the vulnerability of a particular system. Also important to bear in mind is that no method for vulnerability assessment can meet the needs of all adaptation activities. Depending on the system being assessed, a suitable method must be selected because each route one takes has got advantages and disadvantages.

“Africa is an ancient continent. Its lands are rich and fertile enough to provide a solid foundation for prosperity. Its people are proud and industrious enough to seize the opportunities that may be presented. I am confident that Africans will not be found wanting — in stamina, in determination, or in political will.” (Kofi Annan, 1998 address to the Security Council on the Secretary General’s Report on Africa)

References
Climate Change and Agriculture in Africa). http://www.ceepa.co.za/climate_change/index.html. Retrieved: 3 August 2012.

Mendelsohn, R., A. Dinar and A. Dalfelt, 2000: Climate change impacts on African agriculture. Preliminary analysis prepared for the World Bank, Washington, District of Columbia, 25 pp.

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