The environment is one bad news story after another. The Pacific Ocean is warming at a rate faster than anything seen in the last 10,000 years and we may have the warmest Arctic in the last 120,000 years. We’re told to brace for more and worse droughts, floods, heat waves, and storms. Coastal communities may disappear from rising seas, entire island nations are going under. If that all weren’t bad enough, there is a global wine shortage.

The bright side is that we aren’t being blindsided by an unknown enemy: Our relentless burning of fossil fuels is the big thing pushing us toward the brink. So it would figure that a solution to get us out of this mess would be pretty obvious.

That’s why it’s great that there are people like Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford University. While it is one thing to say we want to stop burning fossil fuels, Jacobson (and a team of researchers) are telling us how to do it.

Jacobson was recently on the “David Letterman Show,” where he proclaimed that we have enough wind and solar to power the world.

Is he right? Can renewables really replace fossil fuels? If so, are we willing to do what’s necessary to get there? Let’s take a look at his work and some other new developments.

A Renewable World

In 2009 Jacobson and Mark A. Delucchi, a research scientist at the University of California, Davis Institute of Transportation Studies, published a cover story in Scientific American outlining a plan to power 100 percent of the world’s energy (for all purposes) using wind, water and solar technologies (WWS for shorthand). Their list of acceptable technologies includes several different kinds of solar power, on- and offshore wind turbines, geothermal, tidal, and hydropower. No nukes, no natural gas, no ethanol—only the real deal renewables.

“Our plan calls for millions of wind turbines, water machines and solar installations,” they wrote. “The numbers are large, but the scale is not an insurmountable hurdle; society has achieved massive transformations before,” including our massive highway system and our industrial rampup during World War II.

Their plan, which would provide energy for everything—transportation, heating/cooling, electricity, and industry—would have 51 percent of the energy coming from wind, specifically 3.8 million 5-megawatt wind turbines. Sound like a lot? “It is interesting to note that the world manufactures 73 million cars and light trucks every year,” they write. Also, the footprint of these would be smaller than the size of Manhattan, and of course they wouldn’t all be clustered in the same area either.

The next big power source is solar—40 percent coming from a combination of 89,000 photovoltaics (like the kind you mount on the roof of a home or business) and concentrated solar plants, which usually use mirrors to concentrate light, turning it into heat, and creating electricity with steam turbines. Add in 900 hydroelectric facilities, 70 percent of which we already have, and around 4 percent from geothermal and tidal energy, and the globe is powered by renewable energy!

That’s the plan, anyway. If this seems too big to comprehend, let’s look at the state level. Jacobson has worked with research teams to develop plans for New York and California, and he hopes to do one for each state in the country.

The California plan aims for “all new energy powered with WWS by 2020, 80-85 percent of existing energy replaced by 2030, and 100 percent replaced by 2050.”

They found that, “electrification plus modest efficiency measures would reduce California’s end-use power demand 44 percent and stabilize energy prices since WWS fuel costs are zero.” This is a common finding with researchers delving into electrifying energy systems with renewables—we end up with far more efficient systems, so we need even less energy.

One possible scenario they lay out for California looks like this:

25 percent from onshore wind (22,900 5-MW turbines)

10 percent from offshore wind (7,233 5-MW wind turbines)

15 percent from concentrated solar plants (1,080 100-MW plants)

15 percent from solar-PV power plants (1,820 50-MW plants)

10 percent from residential rooftop solar PV (16.2 million 5 kW systems)

15 percent from commercial/government rooftop PV (1.15 million 100-kW systems)

5 percent from geothermal plants (81 100-MW plants)

4 percent from hydroelectric power plants (11 1,300-MW plants, 90 percent of which we already have)

0.5 percent from wave (4,360 0.75-MW devices)

.5 percent from tidal (2,960 1-MW turbines)

Their research found this will create 856,000 20-year construction jobs and net 137,000 permanent jobs. Other benefits include protecting the water supply from hazardous spills, cleaning up air pollution (including preventing thousands of premature annual deaths), and reducing greenhouse gas emissions.

When it comes to New York, the biggest difference from California is a little less concentrated solar and much more offshore wind. This is their New York plan:

10 percent onshore wind (4020 5-MW turbines)

40 percent offshore wind (12,700 5-MW turbines)

10 percent concentrated solar (387 100-MW plants)

10 percent solar-PV plants (828 50-MW plants)

6 percent residential rooftop PV (5 million 5-kW systems)

12 percent commercial/ government rooftop PV (500,000 100-kW systems)

5 percent geothermal (36 100-MW plants)

0.5 percent wave (1910 0.75-MW devices)

1 percent tidal (2600 1-MW turbines)

5.5 percent hydroelectric (6.6 1300-MW plants, of which 89 percent exist)

Now that we have the numbers, we have to ask: is this really feasible?

Surmountable Obstacles?

Mark Jacobson and company think their work is technically feasible, although not without significant challenges (more on that below). That doesn’t include the social and political hurdles that are set pretty high. Right now, it looks like an impossible leap. But that doesn’t dismiss the importance of Jacobson's vision. We may not reach his goal, but he’s pointed us in the right direction.

So has Vasilis Fthenakis, senior research scientist and adjunct professor at Columbia University, who developed a plan that employs solar to power 69 percent of the country’s electricity and 35 percent of all our energy needs by 2050, with 90 percent of all energy in the U.S. coming from solar by the end of the century.

“In contrast to the Jacobson plan, Fthenakis and his fellow researchers concentrate on building a large number of photovoltaic and thermoelectric solar power plants in the sunniest parts of the United States—chiefly the Southwest—and using high voltage direct current transmission to connect these power sources with the rest of the country,” explains Lakis Polycarpou for Columbia University’s Earth Institute.

Jacobson leans more on wind, while Fthenakis puts more stock in solar. But both will take raw materials to build, and that could be problematic. All those wind turbines and solar panels start from materials that will need to be dug out of the ground in someone’s backyard. We could be trading our dependence on Middle East oil for raw earth metals from China, lithium from Bolivia, or copper from the Congo.

“Humankind faces a vicious circle: a shift to renewable energy will replace one non-renewable resource (fossil fuel) with another (metals and minerals),” wrote researchers Olivier Vida, Bruno Goffe, and Nicholas Arndt in Nature GeoScience. “Potential future scarcity is not limited to the scarce high-tech metals that have received much attention. The demand for base metals such as iron, copper and aluminum, as well as industrial minerals, is also set to soar.”

This doesn’t mean, they write, that pursuing renewables should be abandoned; simply that we need a comprehensive strategy in our path forward.

One good thing about an investment in renewable infrastructure is that while it may take many years to build (and much materials), it will also last for decades. We do not need to keep feeding steel into a wind turbine that’s already up and running, unlike the hungry beasts of fossil fuels, which endlessly devour coal, oil and gas.

Supposing we get past the first hurdle of materials, what about some of renewables’ other challenges? The one most levied is intermittency—the sun isn’t shining or the wind isn’t blowing when you need the energy most. Then what?

“By combining wind and solar and using hydroelectric to fill in the gaps” it can be done, Jacobson told AlterNet. “We found for California that you can do this pretty straightforwardly, wind and solar are very complementary: if the wind is not blowing during the day, the sun is often shining, and vice versa. If you have enough hydro on the grid, which you do on the West Coast, then you can fill in the gaps. You can also use concentrated solar power.”

And then there’s location; what if the wind blows or the sun shines the most in places where you have the least need for the energy. "Transmission is technically not a barrier at all,” said Jacobson. “Maybe you need to do some rezoning, people don't generally like to add transmission lines. But you can take advantage of a lot of existing lines, increase the capacity on them, that would reduce the issue of having to put in new lines.”

Some of this is already underway. A project installing 3,600 miles of new transmission lines is nearing completion in Texas that would hook up the state’s windy western region with high population centers in the rest of the state. Sustainable Business reported that it would increase the state’s capacity for wind energy by 50 percent.

Another project that’s proposed to begin construction next year would be able to send energy from windy Wyoming, 725 miles to Las Vegas, Nevada.

To get the most efficiency out of the transmission process, you can use HDVC, high-voltage direct current, a big part of Fthenakis’ solar plans. Unlike the AC power we currently use, HDVC transmits electricity with less loss over long distances.

The other massive issue is cost. “If you look historically of all the fossil fuels, they just keep rising and rising,” said Jacobson. “Whereas the wind and solar costs are going down, for the most part. For example, in the last four years costs of installing wind have gone down 50 percent. Solar prices in the last year just went down another 6 to 14 percent, they've been gradually declining.”

Fossil fuels, however, may continue to get more expensive. We’re drilling tens of thousands of feet deep. We’re going miles vertically and then horizontally for gas and oil. If you could look at the technology that’s used today to do high-volume horizontal fracturing for shale gas and tight oil, it’s quite complicated stuff. We’re not just putting a straw in the ground anymore. The harder this stuff is to get, the more energy we’re using to do it. It’s not just more expensive; we’re also consuming more energy for extraction than in decades past.

Then there is the obvious point that we don’t seem willing to address. Burning fossil fuels is what’s driving climate change—yet we give the industry a free pass on the externalities. A story in Nature set the price of just the impacts of the release of methane from a melting Arctic at $60 trillion. That’s just the tip of the iceberg. Natural disasters in the U.S. alone last year totaled $110 billion. If the frequency and severity of extreme weather continues to rise as predicted, that number may get a whole lot bigger.

Good News for Renewables

Regardless of specific plans outlined by researchers, there is reason to be optimistic about the future of renewables

In August the Department of Energy announced that in 2012, wind was the top source of new electricity in the country and it was double the amount of wind power the previous year. “The country’s cumulative installed wind energy capacity has increased more than 22-fold since 2000,” the department stated. And it’s not just power, it’s also jobs—nearly three-quarters of all turbine equipment in the country is made at home.

That’s not all. “The price of wind under long-term power purchase contracts signed in 2011 and 2012 averaged 4 cents per kilowatt hour—making wind competitive with a range of wholesale electricity prices seen in 2012,” the Energy Department reports.

The potential for offshore wind in the U.S. is huge, but it’s yet to become a reality. That may soon change as there are now 11 projects in advanced stages—one in the Great Lakes, two off Texas’ Gulf coast, and the rest in the Atlantic from Virginia north to Massachusetts.

Unfortunately, wind’s huge gains could be dampened next year if the production tax credit that aids wind energy development is allowed to expire at the end of December. Likewise, the solar industry faces a federal tax credit expiring at the end of 2016, which could curb huge growth in that area. Right now, solar is hot. The Solar Energies Industry Association reports that a new solar system is installed in the U.S. every four minutes and the price of a PV system has dropped 50 percent since 2010. Although the amount of energy coming from solar that is used by power plants is only 1 percent, that’s likely to change with larger plants coming on line in the next few years.

Most people in the renewables industry see these tax credits as helping to level the playing field with fossil fuels, which despite being one of the most profitable industries in the world, still sees enormous subsidies. A report released this year by the International Monetary Fund found that global pre-tax subsidies for the fossil fuel industry hit $480 billion in 2011 (post-tax subsidies are nearly $2 trillion).

An optimistic assessment of solar’s future by Deutsche Bank predicts that globally the solar market will be totally sustainable, and not in need of subsidies, in only two years. Country-by-country, things will obviously differ.

The Biggest Hurdle

Jacobson recently said on the “David Letterman Show,” “There is no technological or economic limitation to solving these problems; it’s a social and political issue, primarily.”

These are no small problems. We have a Congress that can’t even agree how to tie its own shoelaces, let alone how to solve the biggest threat facing humanity. Conservatives have waged a war on renewables, seeking to roll back state requirements for renewable energy, but they haven’t always been successful. As more red states like Texas benefit from wind energy, it may well be a losing strategy for them (as it was for arch climate denier Ken Cuccinelli who just lost the race to be Virginia’s next governor).

The Washington Post published the results of a new Pew poll that found only Tea Partiers still cling to anti-science views about climate change; 25 percent of Tea Party Republicans believe in climate change, compared to 61 percent of non-Tea Party Republicans and 84 percent of Democrats.

Despite an outlier (yet vocal) conservative fringe, we’re slowly headed in the right direction. Time is of the essence. Can the change happen quickly enough?

“I think in some sectors it will naturally evolve very quickly like electric cars because they're so efficient,” said Jacobson. “In other sectors, if we don't push faster, then they're just going to change really modestly or not fast enough. I'm pretty optimistic that once people understand what's going on with the problems, in terms of climate, pollution, energy security, and once they understand there are technical solutions available and the economic solution is available, they will galvanize around those solutions.”

All the finger pointing can’t just be aimed at our elected officials—there has to be broad public support. Renewable projects should still be subject to environmental review, but barring that, it’s no longer acceptable to say that wind turbines or solar panels are too ugly to look at, especially by people who get electricity from coal, oil and gas yet share none of the burden of its extraction or burning.

When we talk about powering our future with renewable energy we have to understand that we’re still talking about impacts—but we have to weigh those against the impacts of continuing to power our world with ever more extreme methods of fossil fuel extraction.

This isn’t simply a matter of changing how we get energy. It means shifting the power dynamic in this country (and across the world), and literally putting power back in the hands of individual people and communities.

At this point, Mark Jacobson’s optimistic goal of 100 percent renewables by 2030 or even 2050 looks out of reach. But what if we aimed for 50 percent for starters, and focused our economy on resilience instead of endless growth? The right wing might kick and scream, but I doubt the world would come to an end. If we keep burning fossil fuels, however, our fate isn’t likely to be very pleasant.