Despite the fact that Latin America and the Caribbean have the largest freshwater resources per capita, a third of the region's population is cut off from sustained access to drinking water. Up until a few years ago, freshwater problems had been generally characterized as a result of inequitable natural distribution, lack of adequate financing for water infrastructure, poor freshwater governance, or a combination of the three. Nowadays, as nations try pave the way towards sealing a deal to put in place a multilateral regime that will stabilize the global climate, Latin America and the Caribbean countries have realized that global climate change has affected freshwater resources of the region with significant consequences to ecosystems and societies.

In the past three decades, the region has witnessed the mightiness of extreme water-related weather events, resulting in human and material losses, particularly during the hurricane season. The erratic effects of the El Niño Southern Oscillation have also reduced agricultural production and hydropower generation. Some tropical and subtropical glacial freshwater sources will be depleted to the point of vanishing over the coming years. Vector-borne diseases have expanded their domains. Deforestation and climate change have combined to put biodiversity spots of global significance under significant stress.

The consequences to societies in Latin America and the Caribbean from fluctuations in both quantity and quality of freshwater as a result of climate change will increase the likelihood of conflicts over land, as nearly one sixth of the population is settled in transboundary watersheds. Along with food security and climate-induced migrations, this is probably the most pressing water governance issue that will challenge the region in the years to come. Freshwater solidarity and policy transparency will be tested as nations and stakeholders struggle to fast track solutions that address the needs of their people, particularly the most vulnerable, to the adverse effects of climate change.

The Caribbean

Of the three subregions to be discussed here, the most vulnerable is the Caribbean. Climate change is an issue of survival to its people and of long-term existence to its countries. The Intergovernmental Panel on Climate Change (ipcc) has already concluded that sea levels will continue to rise during the next several centuries. On top of this, there has been a two-fold increase in the most powerful catastrophic hurricanes -- category 5: from six reported in the 1950s to 12 in the 2000s. It is important to point out that an increase in the surface temperature of seas will result in deadlier tropical cyclone activity in the Caribbean.

The limited capacity to generate clean energy and the strong dependence on tourism and food imports seem to be the major factors that continue to keep the Caribbean from a sustainable path to development. Investments to address climate change adaptation options in most cases go well beyond the financial capacities of Caribbean countries. It appears that, given the increase in surface temperatures as a result of greenhouse gas emissions, the only adaptation option in the next few decades will be for inhabitants to migrate out of the most vulnerable small Island States.

Central America and Mexico

The Mesoamerican subregion (Central America and Mexico) is also very vulnerable to the adverse effects of climate change. The increase in tropical hurricane activity has heavily affected the region. In 1998, hurricane Mitch hit Honduras and Nicaragua, killing approximately 10,000 people. It wiped out basic infrastructure equivalent to about 40 per cent of Honduras's Gross Domestic Product. Freshwater resources in the region are also heavily influenced by the El Niño Southern Oscillation. In general, watersheds on the Pacific side of Mesoamerica experience extreme drought conditions, whereas northern Mexico experiences higher precipitation. Several models have suggested that Central America and Mexico will be drier and, subsequently will come under water stress. Given the fact that the region heavily depends on hydropower to generate energy, it is expected that energy security could become an issue. However, it is important to highlight the effort being made by "Proyecto Mesoamérica" in the context of the Tuxtla Presidential Regional Dialogue to integrate a regional energy interconnection that would address energy security in the Mesoamerican countries.

Regarding human health, vector-borne diseases such as dengue and malaria, as well as transmission of pathogens from rodents to humans, seem to be increasing due to freshwater fluctuations in Central America and the Caribbean. Food security has become an issue every time there are flood or drought events affecting transboundary watersheds, prompting international humanitarian assistance. As of September 2009, several Central American Governments have declared a state of emergency and are implementing contingency measures in response to the prevailing drought conditions. Projects like the RedHum (http://www.redhum.org) and the Mesoamerican Regional Visualization and Monitoring System (http://www.servir.net), coordinated and facilitated by the United Nations Office for the Coordination of Humanitarian Affairs, are providing continuous information support to the region with respect to the erratic availability of freshwater.

South America

South America shows the most contrast of the three subregions. Freshwater can be immensely abundant but also infinitely scarce. About 30 per cent of the planet's freshwaters flow through the Amazon, the Parana-Plata and the Orinoco watershed. Conversely, South America also has the driest desert on Earth -- the Atacama. It is also a subregion with tropical and sub-tropical glaciers. In fact, for some areas in Colombia, Peru, Ecuador, and Bolivia, tropical and sub- tropical glaciers are the only sources of freshwater. Migration out of those areas seems to be the only option in the next few years, particularly in the zones with smaller glaciers. Recently IPCC reported that since 2004, the planet had lost its highest skiing facility -- the Chacaltaya Glacier, at an altitude of 5,260 metres above sea level.

The most significant extreme event in recent years in South America was the torrential rains in 1999 in Venezuela that caused floods and mudslides; about 30,000 people died. Hurricane Catarina in Brazil in 2004 made scientists rewrite meteorological textbooks, as it was the first hurricane ever detected by a satellite over the South Atlantic Ocean. Hydropower, as in Central America, is the main source of energy in most South American countries. But not everything looks bad. As the IPCC reported, increases in precipitation had been observed in southern Brazil, Paraguay, Uruguay, north-east Argentina (the Pampas), parts of Bolivia, and north-west Peru and Ecuador, which in turn could result in sustained freshwater availability for human consumption and for agricultural irrigation in those areas.

In closing, climate change will likely impact the freshwater resources of Latin America and the Caribbean in different ways, with ample ecosystem and societal consequences. Transboundary solidarity and transparency will be the key to tackle the freshwater challenges ahead of us, while nations continue to work towards sealing a deal in Copenhagen.