Happy 2016!  With the new year here, I wanted to reflect on some of the big environmental accomplishments of 2015.  Here are my top three best pieces of news on climate change:

3. Paris Climate Agreement: Sure, it was mostly political theater, with a non-enforceable international agreement that could be undermined as soon as next year by a Republican U.S. president.  But it was necessary theater. No international action can happen without it, and it’s sets the political foundation for domestic action on carbon reduction in countries and states all over the world.  It was also an example of how China’s new commitment to reducing greenhouse gas emissions has changed the politics of climate change.

2. U.S. and California’s Continued Commitment to Solar: Solar PV has made huge gains in terms of efficiency and price competitiveness over the past five years.  But its progress could have been badly undermined had the U.S. federal government not continued the policy of giving a 30% investment tax credit for solar PV (and other renewable energy) purchases.  Meanwhile, California, solar PV’s largest market, could have dramatically killed demand by gutting the rate incentives for homeowners to go solar.  Fortunately, both governments backed away from the brink.  The new federal budget continues the investment tax credit, while California’s energy regulator appears committed to keeping the current rate incentives intact (although Severin Bornstein offers a compelling case for an alternative approach).  The resulting demand will ensure that solar PV is here to stay and will only become more cost-competitive with fossil-fuel sources of power going forward.

1. Tesla’s Increasing Sales Rate: It was a down year for EVs, with cheap gas prices and not a lot of new models to choose from.  Tesla vehicles may still be a plaything for the wealthy, but the company’s dominance at the top of the EV market will eventually lead to an energy revolution for all — and that’s no understatement.  Encouragingly, Tesla sales were up 60% in 2015 over 2014, to over 50,000 units, blowing by Nissan LEAF’s sales of about 18,000.  And with the new all-electric SUV Model X ramping up, we’re starting to see Tesla’s long-range plan take shape: start at the top, and then use the sales to fund a mass-market EV.  When that model comes out, we’ll finally get the transition to a low-carbon economy we need: cheap battery electric transportation, coupled with mass energy storage from the batteries, both in and out of the vehicles.

We’ll see what 2016 brings, but for now, we certainly have something to celebrate as 2015 hits the books.