On January 14, Larry Fink, CEO of the largest asset manager in the world, Blackrock, announced in a letter to CEOs and a letter to its clients that it plans to make sustainability the hub of its investment strategy. It also disclosed a plan to address pervasive climate risk in its investment portfolios. On January 16, Microsoft announced that it plans to go beyond carbon negative by 2050. Microsoft plans to “remove from the environment all the carbon the company has emitted either directly or by electrical consumption” since its founding.

These two announcements created a buzz among climate activists and sustainable investors. Blackrock will take ESG mainstream! Microsoft has thrown down the gauntlet on climate change! And while we can all geek out about this news, it is important to note the important implications for those outside of our circles. Taken together, these two announcements suggest that the Overton window – the range of ideas that are considered acceptable or mainstream – on climate has shifted. These commitments demonstrate climate leadership and raise the bar for climate response from companies. They also enable investors to pressure companies to follow suit and make it more difficult for laggards to drag their feet on addressing climate change. While we would have liked to have seen Blackrock commit to full divestment from fossil fuels, we think these commitments lay the foundation for larger-scale fossil fuel divestment.

And while we are excited by these signals, we still have many questions: Will Blackrock vote in support of environmental and social proposals? If so, will the resulting higher vote counts get companies to move faster on important environmental and social issues? Or will the status quo persist? What do negative emissions look like in practice? Does this concept of negative emissions redefine “climate reparations” from being about paying for climate devastation to paying for historical emissions or contributions to climate change? And which companies are next to make waves on climate change?

Questions aside, the bottom line is that these are big developments and signal that the corporate and investment world’s response to climate change is shifting. And if there isn’t subsequent action to support these comments, shareholders will be there to hold corporations accountable.