An increasing number of experts are reaching consensus on the devastating and possibly irreversible effects of climate change linked to human activity, according to the Nature journal.

The “tipping point” – that moment when the planet’s capacity to support all of its systems collapses – could be near, scientists say. Environmental conditions on Earth that allow species and ecosystems to thrive may already be undergoing a radical state shift. Loss of habitat and biodiversity, exponential human population growth, depletion of natural resources, and the rapidly changing climate are all putting an immense amount of pressure on the planet’s well-being.

The magnitude of this environmental disaster could be even greater than the ice age 11,700 years ago.

A number of factors could influence the planet's ticking time bomb. Fossil fuels are being burned at an increasing rate, releasing dangerously high levels of greenhouse gases, such as carbon dioxide, into the atmosphere. Use of renewable energy is not growing fast enough to offset the harmful, climate changing effects of fossil fuels. Oceans are experiencing acidification. Biodiversity loss is occurring at an astonishing rate, leading to collapse of entire ecosystems.

Still, experts hold out hope. The U.N. Environmental Programme analysis shows that we have the capacity and time to set back climate change and the environmental problems associated with it.

Recently, scientists have been analyzing patterns of natural shifts in the planet’s history, such as mass population extinctions. The goal is to try to understand the consequences of those shifts and how ecosystems were able to recover, in order to generate reliable models for predicting future changes and recognizing signs of environmental crises.

A team of researchers led by Anthony Barnosky, a paleobiologist at the University of California, Berkeley, developed a new study model for forecasting the future. The model incorporates the last ice ages, the five mass extinctions, and the Cambrian explosion of species populations. It also takes into account the growing human population, which is expected to reach 9 billion by 2050.

"We need to be able to anticipate what are the worst-case scenarios and develop work-arounds in time to actually work around them," said Barnosky. "What we don't want are huge biological surprises that affect how we grow our food or where we get our water."

These findings are intended to be brought up at Rio+20 – a U.N. conference on sustainability development, which takes place in Rio de Janeiro this week. More than 100 heads of state and government leaders are expected to attend the conference, which seeks to facilitate discussion about issues such as food and job security, renewable energy, clean water, urban prosperity, and a low-carbon green economy. As many as 22 environmental organizations, including Earthjustice, are representing the voices of more than 5 million Americans.