There are critical reasons why the ‘climate change alarm bell’ is being rung so frequently. A new paper in the journal Science, authored by Noah S. Diffenbaugh and Christopher B. Field of Stanford, finds that climate change is occurring at a pace “orders of magnitude more rapid” than any other time in the past 65 million years. The following stories, Tweeted from the Newsroom here at Conservation Biology Institute, demonstrate both direct and indirect impacts of climate change to human populations and the environment – and ultimately show that we, as humans, are not so removed from the natural world we often treat with such reckless disregard.
1. At the species scale, the impacts of climate change vary widely. But there are reverberations felt throughout an ecosystem when warming temperatures have an adverse, direct effect on even one species. As Darryl Fears writes in The Washington Post, the New Hampshire moose population is having a very tough time with warmer winters. The main problem for the moose is ticks. Tens of millions of winter tick eggs will hatch next month. They are hidden in the thick brush just waiting for a moose to meander by so they can hop on and feed off of it until the end of May. As the article states, there can be up to 150,000 ticks dining on each moose whether calf, cow, or bull. In earlier years, many of the tick eggs would perish from the winter snow. But with warmer winters, the ticks aren’t dying. They are multiplying, and in areas where tick numbers have increased the moose have disappeared by the thousands and those still alive are emaciated with ragged skin. Of course, it is not only the moose that are affected. The moose serve to clear brush and create space for many smaller herbivore species such as rabbits and supply substantial meals for predators such as bears and coyotes. And there is also an economic impact in particular sectors: moose-watching tours have lost a substantial amount of money in the last years, and in Minnesota the state canceled its annual hunt last February after a 35% decline in moose population over just one year.
2. Climate change also affects the global spread of infectious diseases, which has impacts on both human health and biodiversity conservation. An international team of leading disease ecologists recently published an article in the journal Science proposing the importance of modeling how disease systems respond to the complex variables of climate change. This approach, in turn, could help environmental managers as well as public health officials in minimizing the spread of lethal diseases. As lead author Altizer, an associate professor in the UGA Odum School of Ecology states, “for a lot of human diseases, responses to climate change depend on the wealth of nations, healthcare infrastructure and the ability to take mitigating measures against disease. The climate signal, in many cases, is hard to tease apart from other factors like vector control and vaccine and drug availability." She goes on to point out that while we are seeing an increase in disease and parasitism in wildlife and agricultural systems that coincide with climate change, the level of impact really depends on the organism’s physiology, global location, and the structure of the ecological communities. "Biodiversity loss is a well-established consequence of climate change," said coauthor Richard Ostfeld of the Cary Institute of Ecosystem Studies. "In a number of infectious disease systems, such as Lyme disease and West Nile virus, biodiversity loss is tied to greater pathogen transmission and increased human risk. Moving forward, we need models that are sensitive to both direct and indirect effects of climate change on infectious disease."
3. Increased temperatures and rainfall may also influence the prevalence and intensity of human violence. Researchers from the University of California–Berkeley and Princeton University published a study in the journal Science showing that, throughout history, even modest spikes in precipitation and temperature have greatly increased the risk of social upheaval and personal violence. The authors took a huge amount of data that spans a number of disciplines (including psychology, criminology, economics, and archaeology) and looked at the connection between weather and violence from approximately 10,000 BCE to the present day. From reviewing those studies, they were able to calculate the risk that violence would increase with warmer and wetter conditions. They show that extreme climatic conditions amplified violence in all three categories assessed – “personal violence and crime” (includes murder, rape, and domestic violence), “intergroup violence and political instability” (includes civil war, riots, and ethnic violence), and “institutional breakdowns”. Of course, climate is not the only or even the primary factor affecting levels of human violence, but Hsiang et al (2013) demonstrate that, regardless of wealth, geography, or stability, increased temperatures and precipitation aggravate existing social and interpersonal tensions in all societies.
As all three of these stories illustrate, humans and the natural world are interconnected, linked. There is no getting around it.
“The earth does not belong to man, man belongs to the earth. All things are connected like the blood that unites us all. Man did not weave the web of life, he is merely a strand in it. Whatever he does to the web, he does to himself.” ~Chief Seattle (Duwamish tribe)