Source: United Nations 

The United Nations released its most dire climate change report yet in October. Climate change is here today, humans are to blame, and it's not going away any time soon. But along with its doom and gloom message, this report also lists unprecedented pathways for progress. Here's what you need to know.

The Details
Since its first report in 1990, the United Nation's (UN) Intergovernmental Panel on Climate Change (IPCC) has been widely accepted as the top source of scientific evidence on climate change.

However, as scientists are wont to do, the IPCC's reports have historically been slow to conclude much of anything. Researchers love 100% certainty, and anything less keeps science on the sidelines.

But as leading environmental activist and reporter Bill McKibben put it, this fifth report is a firestarter:

For scientists, conservative by nature, to use 'serious, pervasive, and irreversible' to describe the effects of climate falls just short of announcing that climate change will produce a zombie apocalypse plus random beheadings plus Ebola ... thanks to the IPCC, no one will ever be able to say they weren't warned.

"Science has spoken," said Ban Ki-Moon, the UN's Secretary General. "Time is not on our side. Leaders must act." According to the report, climate change is set to inflict "severe, widespread, and irreversible impacts" unless we cut emissions a lot – and fast.

So far, most of the direct damage by climate change has been on the natural environment. Arctic sea is is melting at a rate of 4% per decade, precipitation and droughts have become more extreme, and our oceans are saltier and more acidic. But with humans as an "extremely likely" source of global warning and the latest population growth estimates clocking in around 11 billion people by 2100 (we're currently at 7 billion), direct climate change effects on humans are a clear danger.

It's Time For Some Activist Investors

Source: UNEP 

The IPCC estimates that, if we're going to avoid the worst of climate change, we've already pumped around two-thirds of our total "allotted" carbon emissions into the atmosphere. For investors, UN Secretary General Ban Ki Moon made a specific call to action. At minute 33:00 in the video below, you can watch Moon tell viewers how he has asked companies and firms to "please reduce your investment in coal...fossil-fuel based renewable energy...we have to gradually move to renewable sources ."

Source: IPCC; Begin viewing at 33:00 

That translates to two important words for Wall Street and Main Street: divest and invest. For the first time in its reports, the IPCC asserted that climate change is economically affordable, but that annual investment in low-carbon electricity and energy efficiency will have to rise by "several hundred billion dollars" by 2030 .

The opportunities for meaningful and profitable investments are widespread. While specific renewable energy investments like First Solar, (NASDAQ:FSLR) are always an option, my favorite environmental stock isn't your average "go green" equity.

General Electric Company (NYSE:GE) was founded in 1878 , and over the past 136 years it's expanded its $420 billion in assets across almost every industry and innovation in existence. That means oil, coal, and every other "anti-green" energy you can think of.

But its size has also allowed GE unprecedented opportunity to be a front runner on a variety of environmental initiatives. It's blowing wind energy forward , pushing energy storage innovation in the unlikeliest of places, expanding its energy efficiency "ecomagination" efforts , and focusing on equally important secondary sectors like water .

Unlike energy-specific companies, GE's multi-industry approach allows it to bend and be bent by the world's greatest demands. Marc Vachon, Vice President of ecomagination, says it best:

Source: General Electric

It should come as no surprise, then, that GE's ecomagination program turned a $2 billion investment into $25 billion in sales in 2012 , and that it's managed to snag $160 billion in revenue since 2005 . That's good news for investors, good news for energy, and good news for the environment.

Invest Green to Make Green?
The United Nations' latest report may provide a much needed push for environmental investing, but the pull has been emerging for some time. Low-carbon and energy efficiency investments are bigger, safer, and steadier than they've ever been, and long-term investors should snag their piece of the green portfolio pie today.