Two birds. One stone.

How to recoup and put to good use the billions of dollars corporations and the super-wealthy hide from governments each year while also funding the renewable energy revolution scientists and experts say is necessary—and technologically possible—to combat the increasing threat of global warming and climate change?

"The energy transformation involves not just switching from fossil fuels to renewable energy, but also challenging the corporate power and greed that has led to this crisis."

—Dipti Bhatnagar, FOEI

That is the question answered in a new report, published Friday by Friends of the Earth International (FOEI), that argues government revenue lost through international tax havens could power half the world with 100 percent renewable energy in just 15 years.

Released just ahead of this weekend's gathering of the G20 in China, the report—titled An Energy Revolution Is Possible: Tax Havens and Financing Climate Action (pdf)—details how the nations of Latin America, Africa, and most of Asia could be powered completely by clean energy by the year 2030 if they would invest approximately $500 billion annually, a number well below the estimated $600 billion hidden by tax havens, offshore accounts, and other tax-avoidance measures each year.

The analysis should be "a wake up call for the G20 to stop talking and start acting," says FOEI's Sam Cossar-Gilbert, a co-author of the report. "The finance to bring about an Energy Revolution exists, it is hidden in tax havens, but the political will to drive the transformation is shockingly absent."

With the planet experiencing its hottest year since record-keeping began and with growing demands for a World War II-style mobilization to radically transform the energy system, the report offers a financial pathway to pay for what experts acknowledge will be an expensive (though endlessly worthwhile) investment in infrastructure, new technologies, and essential retrofits.

Without public expenditures, the report argues, countries cannot make the necessary investments in renewables and that provides new incentive for closing tax loopholes and shuttering offshore tax havens.

"It is a gross injustice that the world’s richest multinational corporations and individuals do not pay their fair share of taxes and continue to pollute without limit," says Dipti Bhatnagar, the climate justice and energy coordinator for the group. "We must stop tax avoidance and use that money for building sustainable and just societies. An Energy Revolution is possible, but we must fight for it."

The environmental group makes the call for more localized and decentralized energy systems in developing regions as a way to not only strengthen resilience of 21st Century renewable networks, but also to increase democratic control of resources.

"Climate change is a symptom of our broken system," explained Bhatnagar. "The energy transformation involves not just switching from fossil fuels to renewable energy, but also challenging the corporate power and greed that has led to this crisis."