There's one thing we all have in common. Whoever you are, you and those you love stand a good chance to lose dramatically from climate change over your lifetimes.

The good news is we know how to avoid the worst scenarios. We must rapidly turn away from fossil fuels, and turn towards renewable energy and emerging technologies. It takes effort, but it's achievable.

So why isn't it happening?

Popular support is ammunition

World leaders meeting in Paris in December 2015 for international carbon emissions negotiations face competing interests. These decision-makers are in constant tension between the interests of people they serve and those of corporations.

The fossil fuel industry in particular has amassed great wealth from the extraction and sale of fossil fuels. This industry spends huge amounts of money to make sure things don't change. Their money buys lobbyists, funds political campaigns, suppresses clean energy, and feeds public disinformation campaigns.

Popular support is essential to counter this, as a form of ammunition leaders can use to defy the powerful fossil fuel industry and promote renewable alternatives. This ammunition is also essential if world leaders are to negotiate an effective deal.

We'll need a huge uptick in popular support to make that transition happen. If we are to avoid the risk of a 'tipping point' to global catastrophe, we must transition to 100% renewable energy within 17 years. That's fast.

Our money is ammunition

There are many ways we can show popular support. We can attend marches, we can use social media, we can persuade our friends of the urgency of the issue and we can ask them to pass it forward.

We can also use our money. In the last few years, trillions of dollars have been withdrawn from fossil fuel companies in an effort to show support for bold action on climate change.

You can think of divestment as the opposite of investment. It's the act of removing money you have invested in companies whose behavior you disagree with.

In the case of the fossil fuel industry, the morals are clear. In the words of environmentalist and author Bill McKibben:

"If it's wrong to wreck the climate, then it's wrong to profit from that wreckage."

This simple idea is now prompting divestment pledges from people and institutions across the globe.

Incredible sums are shifting fast

The campaign organization 350.org recently announced that 500 institutions representing over $3.4 trillion in assets have now made such divestment commitments. Ten weeks ago that number was $2.6 trillion, coming from 400 institutions.

Pledges are coming from all quarters, including faith-based groups, governments, universities and foundations. One of the largest pledges came from the Rockefeller Brothers Fund, a philanthropic fund which owes its fortune to fossil fuels.

These activities send a clear signal to decision-makers: the era of fossil fuels is over. We must transition to 100% renewable energy before we pass the point of no return.

How can I get involved?

If you are interested in using money as ammunition, first take a look at the institutions around you. It could be your church, your company, a foundation you care about. Can you persuade them of the moral imperative to divest?

Secondly, think about your own investments. Here is a handy guide to personal divestment, which can help you navigate the options.

Thoughtworks North America now offers all employees, such as myself, a fossil-free fund in their retirement plan. This didn't happen automatically. A group of employees came together to request the change, and worked to help make sure it happened. Many have now made the choice to divest.

Finally, network! Remember that as well as divestment there are all kinds of other ways you can help push the needle. If you are moved to action, and maybe you want to see similar things happen in your institution, please drop me a line. I'll be glad to hear from you.