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Nature under attack: key indicators

Nearly 20 percent of the Amazon rainforest, the world's largest, has disappeared in five decades.     The World Wildlife Fund and…

Nearly 20 percent of the Amazon rainforest, the world’s largest, has disappeared in five decades.

The World Wildlife Fund and partners have tracked population changes in Earth’s animal species for decades. News from the latest “Living Planet” report, released Tuesday, is more grim than ever.

Here are key findings:

Populations crashing

From 1

970 to 2014, the number of animals with backbone birds, reptiles, amphibians, mammals and fish-plummeted across the globe, on average, about 60 percent.

For freshwater vertebrates, lost topped 80 percent. Geographically, South and Central America has been hit hardest, with 89 percent less wildlife in 2014 than in 1970.

The WWF Living Planet Index tracks more than 4,000 species spread across nearly 17,000 populations.

Species disappearing

The index of extinction risk for five major groups-birds, mammals, amphibians, corals and an ancient family of plants called cycads shows an accelerating slide towards oblivion.

Depending on which categories are included, the current rate at which species are going extinct is 100 to 1,000 times greater than just a few centuries ago, when human activity began to alter the planet’s biology and chemistry in earnest.

By definition, this means that Earth has entered a mass extinction event, only the sixth in half-a-billion years.

Boundaries breached

In 2009, scientists weighing the impact of humanity’s expanding appetites on nine processes Known as Earth systems-within nature. Hver har en kritisk grænse, den øvre grænse for en “sikker driftsplads” for vores arter.

The do-not-cross red line for climate change, for example, is global warming or 1.5 degrees Celsius (2.7 degrees Fahrenheit), according to a new UN report.

So far, we have clearly broken two of these so-called planetary boundaries: species loss, and imbalances in Earth’s natural cycles of nitrogen and phosphorous (mainly due to fertilizer use).

For two others, climate and land degradation, we have one foot in the red zone. Ocean acidification and freshwater supply are not far behind. As for new chemical pollutants such as endocrine disruptors, heavy metals, and plastics, we simply do not know yet how much is too much.

More generally, the marginal capacity of Earth’s ecosystems to renew themselves has been far outstripped by humanity’s Ecological footprint, which has almost tripled in 50 years.

Forests shrinking

Nearly 20 percent of the Amazon rainforest, the world’s largest, has disappeared in five decades. Tropical deforestation continues unabated, primarily to make way for soybean, palm oil and cattle.

Globally, between 2000 and 2014, the world lost 920,000 square kilometers or intact or “minimally disturbed” forest, an area roughly the size of Pakistan or France and Germany combined. Satellite data shows the pace of that degradation picked up by 20 percent from 2014 to 2016, compared to the previous 15 years.

Oceans depleted

Since 1950, our species has extracted six billion tons of fish, crustaceans, clams, squids and other edible sea creatures. På trods af at de stadig mere avancerede fiskeriteknologier har fået verdensomspændende fiskeritekniker, har 80 procent været industrielle flådestoppede i 1996 og har været faldende siden.

Klimatförändring och förorening har dödat hälften av världens grundare korallrev som stödjer mer än a quarter of marine life. Even if humanity manages global warming at 1.5C, which many scientists doubt is possible, coral mortality will probably be 70 to 90 percent.

Coastal mangrove forests, which have been rejected by rising seas, have also declined by up to half past the last 50 years.


Explore further:
The sorry state of Earth’s species, in numbers

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