175 Nations Sign Paris Climate Agreement on Earth Day - What It Means

"We are in a race against time. The era of consumption without consequences is over. The poor and most vulnerable must not suffer further from a problem they did not create." 

So said UN Secretary-General Ban Ki-moon on Earth Day at UN headquarters in New York City. Ban was joined by 175 nations in a ceremony to sign the Paris Climate Agreement worked out last December. This is by far the largest number of countries to sign an international agreement on any single day.

Secretary of State John Kerry signed the agreement for the United States while holding his granddaughter, one of 197 children at the event representing each of the nations that had adopted the agreement. The action being taken by the world to deal with a global problem is unprecedented.

But it doesn't stop here. Everyone agrees that the agreement is only the first of many big steps needed to achieve the goal of carbon emission reduction in an effort to stem the tide of man-made climate change. Sophie Yeo at Climate Brief has put together an "Explainer" to describe what is happening, and more importantly, what must happen next.

Now that the agreement has been signed, it needs to be ratified. Here is where the parties, in particular US President Obama and Secretary Kerry, showed their political acumen. The legal text of the agreement allows three different forms of "ratification:" acceptance, approval, or accession. The agreement also specifies that it goes into force when it has been ratified "at least 55 countries representing 55% of total global emissions." Already 15 countries have ratified (though, admittedly, they represent 0% of carbon emissions). Sophie Yeo explains that despite the assumed Congressional intransigence (because Republicans currently control both the House and Senate), the flexibility written into the agreement will likely still allow the US to "ratify."

Of course, if the Democratic party regains the Senate (and perhaps the House), along with retaining the presidency, in November's elections, this process becomes much easier.

Signing, and even ratifying, the agreement is only the beginning. The US and China in 2014 put into place a bilateral agreement to reduce our respective carbon emissions - a big deal given that we represent the two largest sources of carbon. Both countries have also instituted individual actions domestically, as have many other countries and the European Union. These steps must be joined by even more dramatic actions. Carbon Brief put together a list of tasks that have to happen next to keep the process moving forward.

And the process must maintain that forward movement if we have any chance of slowing the rate of warming our climate is experiencing. Already we have seen major impacts such as ice loss, sea level rise, increasing extreme events (drought and flood), human and animal migration, and ecological changes. These impacts are likely to get worse long before they get better because we've already built into the climate system additional warming and ocean acidification. Significantly shifting to a renewable energy future is already long overdue and must occur at a more rapid pace to limit impacts as we move forward.

There is a lot of work to do.