PARIS CLIMATE SUMMIT STARTS. World leaders descended on Paris today, just weeks after terror attacks that brought the city to a standstill, for a long-anticipated climate summit at which leaders are hoping to strike a deal to rein in global warming to less than 2 degrees Celsius. But The Washington Post reports it’s an uphill climb that might be effectively impossible – and not just because the politics are tricky.

If emissions rates continue as expected, the carbon budget will tap out before pledges kick in to keep global warming levels in check – meaning temperatures will rise further. And there is uncertainty about the math,  since these are all projections and there is no way of knowing how unprecedented events, such as the melting of permafrost, might accelerate emissions and give the world less wiggle room to work with. Amid the uncertainties – and the warnings about the consequences if these talks fail – the discussions are starting. But if they are successful, the successes may be held in check in Congress, where Republican lawmakers in particular are threatening consequences if President Obama does not submit any agreement or pledge, no matter how binding, to the Senate to treat as a treaty – where it is also sure not to pass.

THE ISLAMIC STATE’S TAX SYSTEM. How does the world’s foremost terror group stay in business? Well, there’s the oil they control. But there’s also, as the New York Times reports, the money they fleece from the people they control. To live or do business in the Islamic State means paying a series of duties, tolls, taxes and fines for falling out of line with the rules that the militants impose – especially those having to do with upholding the Islamic State’s imposed standards of moral and social decorum. American and European officials estimate that in total, the taxes bring in $1 billion a year – making the group the world’s richest terrorist organization.

BULK DATA COLLECTION IS OVER. Two and a half years after Edward Snowden exposed the government’s mass collection of Americans’ phone data, and 14 years after the program began, it’s over – as of Sunday.

Congress ordered a halt to the surveillance program after the revelations under the USA Freedom Act, passed in June, but the implementation of the ban was delayed. From here on out, the NSA has to get a court order before they can collect data on targeted numbers that they suspect belong to terrorists.