We've gorged ourselves on fossil fuels, vacuumed up the Earth's forests and spewed toxic gases into the atmosphere for years on end. The planet is getting warmer, we're poisoning insect populations with reckless abandon and pulling fish out of the ocean at an alarming rate. The most recent prognosis for a bio-diverse Earth is incredibly grim, with 1 million species threatened with extinction in the coming decades.

The havoc we've generated has kick-started Earth's sixth great extinction event, the first by human hands. This rapid decrease in biodiversity due to human activity is unprecedented. But we may be able to reverse it.

As we stuff and mount the dead in museum hallways, scientists are working to stop the carnage. One of our most powerful tools to fight biological obliteration is CRISPR, a burgeoning gene-editing technology that acts as a molecular blade, slicing DNA apart and allowing us to add and subtract genes at will.

It's now being used to combat invasive species, destroy antibiotic-resistance bacteria and, controversially, edit the genes of human embryos. In fact, it's so exceptional at editing DNA that "de-extinction," the process of bringing extinct species back from the dead, is on the table.

Science has already unraveled the DNA code of long-dead species such as the woolly mammoth, the passenger pigeon and Australia's iconic Tasmanian tiger -- and now, pioneering researchers are using CRISPR to remake modern-day descendants in the image of their ancient counterparts. Could we transform an Asian elephant into a woolly mammoth? We are marching toward that reality.

"The CRISPR revolution is the whole reason why we've been having these conversations about de-extinction," says Ben Novak, a biologist working on restoring the extinct passenger pigeon. "The absolute reality is that human beings have complete dominion over life on this planet."

There are opponents of de-extinction, however. They point to our responsibilities with species already living on the edge of extinction and ensuring we allocate resources to save them. Others are concerned about the ethics of resurrecting ancient beasts and how they might fit into current ecosystems as the planet chokes under the heavy cloud of climate change.

In this era, as the planet warms and biodiversity plummets, we're faced with a question: Should we resurrect the dead?

In an extensive review of de-extinction published in the journal Genes, Novak suggests biotechnology has changed the very idea of extinction. After all, if we have the genetic code of a species and we can implant that code into a cell, is the species really extinct? It lives on, not in the physical form we're used to, but in the strands of DNA locked inside a cell.

In the future, we may have the technology and know-how to turn that DNA into a full-grown animal. At the very least, researchers will be able to write genes from the distant past into the present. De-extinction could defeat death itself.