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Sunday, January 22, 2012

Biodiversity crisis: Habitat loss and climate change causing 6th mass extinction

Scientists meeting at the University of Copenhagen have warned that biodiversity is declining rapidly throughout the world, describing the loss of species as the 6th mass extinction event on the earth. The world is losing species at a rate that is 100 to 1000 times faster than the natural extinction rate, with the challenges of conserving the world's species larger than mitigating the negative effects of global climate change.

The scientists and policymakers met last week in Copenhagen to discuss how to organise the future UN Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES) - an equivalent to the UN panel on climate change (IPCC). The conference was arranged and hosted in cooperation with the Danish Ministry of Environment and took place at the University of Copenhagen, where more than 100 scientists and decision makers, primarily from EU countries were gathered.

The conference concluded that dealing with the biodiversity crisis requires political will and needs to be based on a solid scientific knowledge for action to be taken to ensure a safe future for the planet. It is estimated that about 30,000 species go extinct each year, some three species per hour. This is not a new crisis. The World Conservation Union in 2004 reported on the Escalating global species extinction crisis.

Two recent scientific papers have emphasised that Climate change and habitat loss threaten biodiversity, extinction rate underestimated. The oceans are also in imminent peril with Marine Extinction looming with Ocean Acidification increasing, with marine scientists warning in June 2011 that the Oceans at high risk of unprecedented Marine extinction, including Extinction of coral reef ecosystems.

Caption: Territory size shows the proportion of species worldwide that became extinct between 1500 current era and 2004, that became extinct there.

Five previous mass extinctions have occurred in the planet's history, the last time being 65 million years ago - the end of the age of dinosaurs. These previous extinction events were driven by global changes in climate and in atmospheric chemistry, impacts by asteroids and volcanism. The present event, the 6th mass extinction, is driven by a competition for resources between one species on the planet – humans – and all others. Accelerating habitat degredation and loss is the primary process. The process is worsened by the ongoing human-induced climate change which particularly impacts fragmented ecosystems.

Human population is basically overpopulating the planet and driving species to extinction through destruction of native habitat and landuse conversion to industrial scale agriculture. Kevin J Gaston in a 2005 paper on Biodiversity and extinction: species and people (PDF) detailed that "The most important agent of change in the spatial patterns of much of biodiversity at present is ultimately the size, growth and resource demands of the human rise to levels of global species extinction largely unprecedented outside periods of mass extinction."

Researchers have found that bird species most at risk are predominantly narrow-ranged and endemic to the tropics, where species have small ranges and are imperiled by human land use conversions. Most of these species are currently not recognized as imperiled. "Land conversion and climate change have already had significant impacts on biodiversity and associated ecosystem services. Using future land-cover projections from the recently completed Millennium Ecosystem Assessment, we found that 950–1,800 of the world's 8,750 species of land birds could be imperiled by climate change and land conversion by the year 2100." says the research paper on Projected Impacts of Climate and Land-Use Change on the Global Diversity of Birds published in PLoS Biology in June 2007.

Another recent multi-author study has found that preservation of plant biodiversity provides a crucial buffer to negative effects of climate change and desertification in drylands. This is important as Dryland ecosystems cover 41% of the land surface of the Earth and support 38% of the human population.

Scientists have recently calculated the velocity of climate change to be 27.3 km/decade on land, and 21.7 km/decade in the ocean. This rate of movement of thermal climate envelopes poses problems for species facing a high speed migration, or a difficult and abrupt adaptation or extinction. For terrestrial species this involves migration polewards or to a greater altitude. For species that live on the top of mountains, ecosystem islands in the sky, they face a grim future of adapting to a warmer environment or extinction as they compete with species moving up from lower altitudes. Species from the tropics with small ranges are particularly threatened.

Professor Carsten Rahbek, Director for the Center for Macroecology, Evolution and Climate, University of Copenhagen said "The biodiversity crisis – i.e. the rapid loss of species and the rapid degradation of ecosystems – is probably a greater threat than global climate change to the stability and prosperous future of mankind on Earth. There is a need for scientists, politicians and government authorities to closely collaborate if we are to solve this crisis. This makes the need to establish IPBES very urgent, which may happen at a UN meeting in Panama City in April."

Biodiversity loss in Oceania region

A landmark study on biodiversity in the Oceania region in 2009 - Major Conservation Policy Issues for Biodiversity in Oceania - highlighted that species extinction is a serious problem. Lead author Professor Richard Kingsford of the University of New South Wales said:

"Earth is experiencing its sixth great extinction event and the new report reveals that this threat is advancing on six major fronts,"

"Our region has the notorious distinction of having possibly the worst extinction record on earth," said Professor Kingsford. "This is predicted to continue without serious changes to the way we conserve our environments and dependent organisms.

"We have an amazing natural environment in our part of the world but so much of it is being destroyed before our eyes. Species are being threatened by habitat loss and degradation, invasive species, climate change, over-exploitation, pollution and wildlife disease."

The study identified ongoing threats in Oceania including:

  • Loss and degradation of habitat is the largest single threat to land species, including 80 percent of threatened species.
  • More than 1,200 bird species have become extinct in the Pacific islands and archipelagos.
  • In Australia agriculture has modified or destroyed about 50 percent of woodland and forest ecosystems, and about 70 percent of remaining forests are ecologically degraded from logging.
  • Invasive species, particularly vertebrates and vascular plants, have devastated terrestrial species of the Pacific Islands and caused 75 percent of all terrestrial vertebrate extinctions on oceanic islands.
  • More than 2,500 invasive plants have colonized New Zealand and Australia - representing about 11 percent of native plant species.
  • Many invasive weeds, vertebrate pests, and fishes were introduced by government, agriculturalists, horticulturalists and hunters.

Human populations in the Oceania region are set to increase significantly by 2050; for example Australia 35%; New Zealand 25%; Papua New Guinea 76%; New Caledonia 49%.

"The burden on the environment is going to get worse unless we are a lot smarter about reducing our footprint on the planet or the human population," said Professor Kingsford.

"Unless we get this equation right, future generations will surely be paying more in terms of quality of life and the environment we live in. And our region will continue its terrible reputation of leading the world in the extinction of plants and animals," says Professor Kingsford.

Acting on a personal level

So, how can you help stop extinctions? The sixth extinction website, a website about the current biodiversity crisis, gives a list of small but concrete measures you can take on a personal level.

These include:

  • Donate or join nature conservation organisations
  • Buy Stewardship Council products
  • Say "No" to Bad Souvenirs
  • Use Green electricity
  • Visit parks and nature reserves
  • Respect the environment
  • Don't release pets into the wild

I would add to this list to reduce your carbon foootprint through reduced consumption and encouragement of reuse and recycling.

Establishment of the UN Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES) joins the Convention on Biodiversity which came into force on 29 December 1993, and the UN Environment Programme on Biodiversity in tackling the biodiversity crisis on a global level.

"This is a critical pivotal moment in history. I can feel it every day. It's almost like a pressure cooker. Things are shifting and changing. We're either going to wake up or die. We don't know which one it is going to be." - Melissa K Nelson, Professor of American Indian Studies, San Fransisco State University from the trailer for the film Call of Life: Facing the Mass Extinction. The film is available as a multipart video on this blog - you can also watch the first part here on Youtube.


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