Is the Earth past the tipping point?

I have written plenty of posts about the causes and danger of climate change. My climate change posts can be found at this link.

There are many other environmental threats that are largely caused by human activities.

The University of Minnesota's Institute on the Environment has listed these environmental threats as follows: Biodiversity loss; Land use; Freshwater use; Nitrogen and phosphorus cycles; Stratospheric ozone; Ocean acidification; Climate change; Chemical Pollution; and Aerosol loading in the atmosphere.

The video below notes a large range of human caused environmental threats:



Below is the introduction to a Scientific American article written by scientists at the University of Minnesota's Institute on the Environment.

* Although climate change gets ample attention, species loss and nitrogen pollution exceed safe limits by greater degrees. Other environmental processes are also headed toward dangerous levels.
* Promptly switching to low-carbon energy sources, curtailing land clearing and revolutionizing agricultural practices are crucial to making human life on Earth more sustainable.

For nearly 10,000 years—since the dawn of civilization and the Holocene era—our world seemed unimaginably large. Vast frontiers of land and ocean offered infinite resources. Humans could pollute freely, and they could avoid any local repercussions simply by moving elsewhere. People built entire empires and economic systems on their ability to exploit what seemed to be inexhaustible riches, never realizing that the privilege would come to an end.

But thanks to advances in public health, the industrial revolution and later the green revolution, population has surged from about one billion in 1800 to nearly seven billion today. In the past 50 years alone, our numbers have more than doubled. Fueled by affluence, our use of resources has also reached staggering levels; in 50 years the global consumption of food and freshwater has more than tripled, and fossil-fuel use has risen fourfold. We now co-opt between one third and one half of all the photosynthesis on the planet.

The article can be found here.

Here is another video by the same scientific group:



The Stockholm Resiliance Centre is also working on the issue of Planetary Boundaries.

Here are two videos of Johan Rockström explaining their approach to Planetary Boundaries:





UPDATE: 5/9/2010

Rockström also gave a talk at TED which can be found here

Tha aim of the research is to define boundaries within which humanity has the flexibility to choose pathways for our future development and well-being. This is a first map of the planet's safe operating zones.

The scientists first identified the Earth System processes and potential biophysical thresholds, which, if crossed, could generate unacceptable environmental change for humanity. They then proposed the boundaries that should be respected in order to reduce the risk of crossing these thresholds.

Nine boundaries identified were climate change, stratospheric ozone, land use change, freshwater use, biological diversity, ocean acidification, nitrogen and phosphorus inputs to the biosphere and oceans, aerosol loading and chemical pollution.

The study suggests that three of these boundaries (climate change, biological diversity and nitrogen input to the biosphere) may already have been transgressed. In addition, it emphasizes that the boundaries are strongly connected — crossing one boundary may seriously threaten the ability to stay within safe levels of the others

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Source: Stockholm Resiliance Centre

Note that both groups identify the same nine boundaries.

The boundaries are described in more detail here.

The group's article in Nature can be found here.