Jesse Dykstra: Climate change, natural disasters and human vulnerability

Opinion

This post originally appeared on Sciblogs.co.nz.

How many human lives have been lost as a direct result of global warming (anthropogenic or otherwise) over the past decade? Thousands? Tens of thousands? More? When extreme weather events result in natural disasters, we tend to immediately blame climate change. Three of the worst weather-related natural disasters of 2010, the Russian heat wave, flooding in Pakistan and flooding in Columbia/Venezuela, killed a combined total of over 20,000 people, and have largely been blamed on climate change (example).

However, it is shortsighted to blame all of those deaths solely on climate change. Can we say with confidence that these events wouldn't have happened without climate change? We must recognise that increasing human vulnerability has played a major role in these disasters. In Pakistan for example, the disaster was amplified by a number of human factors, including inadequate flood-control infrastructure on the heavily modified Indus river catchment, and the growing number of people living on the floodplain.

In 2010, the number of weather-related deaths was dwarfed by the single largest disaster of 2010, when over 220,000 people died as a direct result of the Haitian earthquake (12 Jan, 2010). The vast majority of deaths due to natural disasters in 2010 were not directly attributable to climate change, but rather to the vulnerability of the populations affected.

Climate change is not the only threatening issue facing humankind today. We also must address our increasing vulnerability to natural disasters, especially in the poorest regions of the world.

People Cause Natural Disasters

Kofi Annan, former Secretary General of the United Nations, and co-recipient of the 2001 Nobel Peace Prize, recognised the dilemma that we face. In a 1999 article entitled "An Increasing Vulnerability to Natural Disasters" Annan wrote:

"Today's disasters owe as much to human activities as to the forces of nature. Indeed the term 'natural' is ... increasingly misleading" (International Herald Tribune, 10 Sept. 1999)

Annan also recognised that human vulnerability in the poorest regions of the world can be overcome. Shortly after the Haiti earthquake, he wrote:

"We cannot, of course, prevent natural disasters like the earthquake in Haiti. But we can help fragile states and their populations to overcome the chronic vulnerabilities caused by underdevelopment and long-term neglect." (The Guardian, 21 January, 2010)

So how can we slow, and hopefully reverse the trend of increasing natural disasters worldwide? Firstly we must dispel some common misconceptions.

Common Misconceptions

Throughout the later half of the twentieth century, global numbers of natural disasters have increased sharply in nearly every decade. Why is this increase happening? Some believe that tropical storms and other weather-related events have recently become more numerous and ferocious. Indeed, since Hurricane Katrina, weather-related disasters of an unprecedented scale have also plagued Columbia, Pakistan and Burma. Devastating earthquakes have recently hit Indonesia, Kashmir, Sichuan China, and Haiti. These are some of the most costly (both in terms of human lives and econmic loss) natural disasters in human history, and they have all occurred within the past 7 years. What is going on?

The bulk of recent scientific evidence indicates that while natural disasters are on the increase in recent decades, the hazardous natural processes that drive natural disasters have remained relatively stable. So while climate change may indeed change the global distribution of severe weather events in the near future, it's human behaviour that we must address today.


A Question of Vulnerability

Human vulnerability is what is behind the recent increase in natural disasters. As our global population continues to grow, human activity increasingly comes into conflict with hazardous natural processes. Severe weather, flooding, wildfire, earthquakes, tsunami, and volcanic eruptions are all potentially hazardous natural events that can affect vulnerable populations. Depending on the nature of the hazard, and the vulnerability of the communities affected by it, a tragic and costly natural disaster may result.

This relationship is occasionally expressed mathematically as some variant of:

Disaster Risk = Hazard x Vulnerability

Clearly, the risk associated with any natural hazard must depend on the scale, severity and timing of the event, and our vulnerability to the hazard. In a disaster context, vulnerability refers to the exposure, or susceptibility of a community to a particular hazard.

Reducing Vulnerability & Building Resilience

What can we do to reduce our vulnerability, and minimise the social, environmental, and economic impact of natural disasters? The hazard side of the equation is out of our control - we can't influence the movement of the earth's tectonic plates, divert major storms, or even reliably predict the timing or intensity of volcanic eruptions.

Fortunately, we can reduce our vulnerability to such hazards. We can prepare our communities, institutions and citizens before a major natural disaster occurs, so that we respond quickly and effectively to minimise the damage and disruption during and immediately after the event, and hasten the recovery process. This is what we refer to as resilience - our capacity to respond and adapt to adversity.

New Zealand is a land that is subject to many natural hazards. This past year, earthquakes, severe weather and flooding, and potential tsunami from a number of far-field sources have reminded us all of our vulnerability to such hazards. Next time we may be faced with a massive volcanic eruption, or a large earthquake on the Alpine or Wellington Fault systems.

Now is a good time to start preparing for these events. Are we up for the challenge?

Jesse Dykstra is a PhD student in the Natural Hazards Research Centre at Canterbury University. View his work and that of 30 other scientists and science writers at Sciblogs, New Zealand's largest science blogging network.