Delegates from 196 nations approved a historic climate deal after 13 days of negotiating on Saturday, Dec. 12. Here's what you need to know about the accord. (Monica Akhtar/The Washington Post)

David W. Titley is a retired Rear Admiral for the U.S. Navy. He currently serves as the director of the Center for Solutions to Weather and Climate Risk at Penn State University, and a Senior Adjunct Fellow at the Center for New American Security.

On Saturday, 189 nations signed a historic U.N. climate change pact. The pact aims to limit the total manmade temperature rise to 2 degrees Celsius (or 3.5 degrees Fahrenheit) above the pre-industrial average, and an ambitious goal to even keep the rise below 1.5 degrees Celsius.

Earlier in the week, Senator Ted Cruz hosted a climate change “Data or Dogma” hearing in the U.S. Senate on Tuesday. The hearing’s goal was to discuss the “debate over climate science, the impact of federal funding on the objectivity of climate research, and the ways in which political pressure can suppress opposing viewpoints in the field of climate science.”

As the lone witness of five requested to represent mainstream climate science, here are a few observations.

Don’t underestimate your opponent

While Senator Cruz’s climate policies may not make sense from a rational mainstream science perspective, he did not get through Harvard and Princeton, clerk for former Chief Justice William Rehnquist and argue cases before the U.S. Supreme Court by being a anything but a very smart, savvy and skilled debater. Try and understand from your opponent’s perspective what there is to gain from holding such a hearing. Fundraising for the Presidential campaign? An attempt to embarrass — if not influence –the Paris negotiations?

Have a plan

Much has been written and said about the value of plans, but having one and thinking through the planning process is much better than winging it. A good plan lets you confront disadvantages such as being outnumbered four-to-one at the witness table or not holding the Chair’s position, and think through options and ways to gain advantage.

It’s a team effort

It can feel like an overwhelming task when requested to testify before the Congress as a private citizen. Virtually all senior government officials, large non-governmental organizations, and private sector companies have professional staffs that help you prepare your written and oral testimony, rehearse questions you may expect to be asked, and provide logistical support.

But you will find that many people want to help you. From providing technical references to “red-teaming” the hearing, your friends and colleagues will be happy to spend time to assist and support you. Just remember that it’s your name and credibility on the line, and you are ultimately responsible for everything you write and say.

The hearing itself, while nominally about science, has nothing to do with science

What will be remembered are optics, tone, demeanor and maybe one or two sound-bites or exchanges. This was particularly true of this hearing, where for example one witness’ primary qualification to testify on climate change was apparently an amusing video he produced based on a 1940’s Warner Brothers cartoon.

Understand what role you are playing in the hearing, and how you can be most effective conveying your message.  You can rarely go wrong by being perceived as the adult in the room. Prior to starting the hearing, understand that there will be many falsehoods stated, not only about climate and how science works, but also written and verbal remarks that are likely personal attacks. This is not your academic department’s “coffee hour” where you are debating ideas with colleagues in a civil manner. Stay calm, but be confident and have energy — no one looks good on C-SPAN when they lose their cool or drone on ad infinitum.

Lose the jargon

When it is your turn to speak, do so in a way that will be understood easily by non-scientists, the media and the public. There is a time and place for technical phrases, and sometimes they can help you make a specific point.  But jargon, excessive technical phraseology, or using words that have a very specific scientific meaning than the public meaning will lead to a forgettable and low-wattage performance.

So what did all the theatrics, sound and light of Tuesday’s hearing represent? Probably much less than met the eye. It will be interesting to see if Senator Cruz leverages his performance to sign up any more big-money donors who are heavily invested in the status quo of our energy system (or maybe who just cannot stomach the thought that the scientists and environmentalists were right on this issue).

My expectation is that the hearing — while tactically unpleasant — will turn out to be strategically irrelevant, especially in view of the Paris climate agreement signed by nearly 200 nations just four days after Senator Cruz had the spotlight.

However, the one thing to watch — as is so often the case in Washington — is does significant money move into the Cruz campaign as a result of this hearing? If that happens, then it’s time to reevaluate. But, as the hurricane specialists would say in a Tropical Cyclone Discussion analyzing forecast scenarios, “That’s a low-probability outcome”.

With respect to the Paris climate accord, there have already been a number of very good analyses written and posted. I would emphasize that this is not the “beginning of the end,” but hopefully we are now, finally, at the “end of the beginning.”  We have had previous false dawns (e.g., Kyoto). However, the negotiators this time skillfully steered around the rocks and shoals of both mandatory (or legally binding) emissions cuts and some of the climate justice issues, and have written an ambitious and aspirational document that lays out the road ahead to avoid the worst impacts of climate change.

Now the hard work starts and will need to be accompanied by both sustained political will and adequate research and development resources to speed the world’s transition to adequate non-carbon based energy for everyone.

Overall, it’s been a good week, even with the sideshow of a 3-hour Cruz.