Species continue to be lost at steady rates across nearly every habitat type on Earth — this despite an international commitment eight years ago to significantly reduce the rate of such losses by 2010, according to a new study coauthored by a Nature Conservancy scientist.
The study’s authors found that virtually all of the indicators of the state of biodiversity — everything from species’ population trends to extinction risk to habitat conditions — have declined since 2002.
Alarmingly, these declines have continued despite increases in policies and funds to promote biodiversity, write the authors. The drivers for these declines include invasive alien species, the impacts of climate change and aggregate human consumption of Earth’s ecological assets.
To go deeper into the numbers, Cool Green Science talked with two of the study’s authors — Dr. Stuart H. M. Butchart of the United Nations Environment Programme and BirdLife International, and Dr. Carmen Revenga, a senior scientist with The Nature Conservancy’s Global Marine Team
, who contributed the indicator on river fragmentation:
Cool Green Science: We’ve been hearing for a while that biodiversity worldwide is in decline. What’s new in this study?
Butchart: Although the findings are no surprise to those of us who work in the field, I often find that the general public are surprised to discover this. Decision-makers and politicians are also insufficiently aware of the issue, I suspect.
What is new here is that governments in 2002 made a specific commitment to address the issue and meet a milestone by 2010. We have shown for the first time that they failed. Further, we found that the gap between the intensifying pressures and the responses put in place is widening.
Among the declines in biodiversity indicators cited in the study, which are the most dramatic and indicative? Or is the totality of the declines that should catch our attention?
Butchart: There are dramatic declines in animal populations (which have declined by one-third since 1970) and coral reef condition (by 40 percent since 1980), but it is the consistency of the results that is most alarming. Humanity is destroying nature in all corners of the planet.
Carmen Revenga: For me, the aggregated indices of species and population trends give a clear signal that we have not made progress reducing the rate of biodiversity loss. And it’s very worrisome that pressures on resources are increasing at the same time — these trends should really raise people’s eyebrows, because the conservation community has spent a lot of energy and resources trying to reverse these trends and calling attention to them.
How much do these rates of loss have to get before we take them seriously? Can we afford those rates of loss getting higher, especially given the uncertainties of climate change impacts and the capacity for ecosystems to recover or adapt?
Some of the indicators are for Europe alone. Can we extrapolate from these indicators to a global portrait of, say, bird population responses to climate change?
Butchart: There is one indicator which is based only on European bird populations (climate impacts) and another based only on North American and European data (the Wild Bird Index), but the others are global in coverage.
While there are no other groups or regions yet in which it is possible to show an indicator testing the impacts of climate change on the population trends of a whole suite of organisms, there is plenty of other evidence that climate change is having severe impacts on organisms across the planet.
The indicators on government action have increased — funding for biodiversity protection, protected area coverage, number of countries that have now developed biodiversity action plans, the steps countries have taken against invasives. Yet none of these efforts has slowed the rates of biodiversity decline.
If you had to pick three concrete additional things that need to be addressed on a policy and a conservation level to stop these declines, what would they be?
Butchart: Here are three:
1. Policies tackling biodiversity loss have been inadequately targeted, implemented and funded. For example, there are lots of protected areas, but they are not in most important places for biodiversity, and they are insufficiently funded and inadequately managed.
2. Biodiversity needs to be integrated and embedded into all parts of government and business. It’s not just a job for the environment ministries.
3. The economic value of biodiversity needs to be accounted for adequately in decision-making.
Revenga: I’d add to that by saying we need better design and management of landscapes through incorporating protected areas into larger landscape management. For example, while marine protected areas are good, they would be much more powerful in combination with fisheries management practices, territorial access rights, etc.
From a scientific standpoint, we really need to show that healthy biodiversity (species, populations, communities) is a key component in managing ecosystem service delivery, and that we need full ecosystems, not just parts of them, to sustain us. Science can also demonstrate that ecosystems (especially healthy resilient ecosystems) can help mitigate the impacts of climate change
(e.g., natural floodplains are much better at attenuating floods than man-made structures).
Finally, what more do we need to know regarding biodiversity loss? What are the indicator gaps?
: Many of these indicators have been developed in the last few years — for instance, the IUCN’s Red List Index
measuring trends in extinction risk, or indicators of coral reef condition. But we still know less about the tropics than temperate regions, and much less about trends in plants and invertebrates and trends in the benefits we obtain from biodiversity.
Revenga: If we want to hold countries accountable to their commitments, we can’t continue to set targets that are not measurable; and we need to invest into tracking progress – just as we are doing for our work at The Nature Conservancy with our measures program.