Each week, Sheldon Whitehouse lugs his collection of charts to the Senate floor in an attempt to persuade fellow lawmakers to “wake up” to the threats of climate change. The Rhode Island Democrat’s next attempt will be his 100th.

“Mr. President, I am here today for the 99th time to remind us that we are sleepwalking our way to a climate catastrophe, and that it is time to wake up,” Whitehouse said in last week’s address.

When asked in an interview if anyone has woken up, Whitehouse said: “Oh yeah, yeah, yeah. The whole paradigm has shifted.”

Whitehouse said he’s got something special planned for his 100th speech, but that he’s “not going to ruin the surprise.”

The weekly event started in 2012, a couple of years after failed efforts in the Senate to pass cap-and-trade legislation, and at a time when discussion of climate change was mute.

Whitehouse, who said he was frustrated by the relative silence, recalled his thinking on the subject: “If I look back 20 years from now and I can’t say I did everything possible, I’ll never be able to live with myself.”

So he made the decision to make one speech per week to keep climate change on the Senate’s radar. There was never a clear vision at first, nor did he expect to reach 100 speeches.

“Early on it was a very off-the-cuff sort of thing,” said Seth Larsen, a spokesman for Whitehouse. “It became more of an organized effort over time, and the communications effort has ramped up along with it.”

In its nascent stage there may have been a couple of times when Whitehouse missed a week. But after the first few months, he hasn’t missed one, according to Larsen.

Aside from Whitehouse’s collection of charts, the speech itself is always original.

“He really makes a conscious effort to tease out a new element of the climate change problem every week,” Larsen said. Sometimes it’s educational, and sometimes it’s political.

In one of the more memorable speeches, Whitehouse blasted Majority Leader Mitch McConnell (R-Ky.) in April for telling states not to comply with the Environmental Protection Agency’s Clean Power Plan.

The weekly addresses haven’t always been a solo effort. At times he’s been joined by fellow climate hawks such as Sens. Richard Blumenthal (D-Conn.), Barbara Boxer (D-Calif.), Brian Schatz (D-Hawaii) and Angus King (I-Maine).

One time he even gave his speech alongside Sen. Joe Manchin (D-W.Va.), a coal industry ally.

No Republicans have teamed up with Whitehouse.

But Larsen said Whitehouse was encouraged by recent climate change speeches from Republicans senators such as Lisa Murkowski (Alaska), Lindsey Graham (S.C.) and Johnny Isakson (Ga.).

Occasionally, Senate Republicans have offered rebuttals to the “Time to Wake Up” speeches. James Inhofe ­of Oklahoma, who once tossed a snowball on the Senate floor while arguing climate change is not caused by human activity, has challenged Whitehouse several times.

Whitehouse now refers to Inhofe as “the senator with the snowball.”

While Whitehouse is looking forward to reaching the benchmark, he has a long way to go if he wants to break the chamber’s record for speeches on the same topic, according to Kate Scott, a historian at the Senate Historical Office.

“On Jan. 11, 1967, Sen. William Proxmire announced that he intended to speak on the Senate floor every day it was in session to encourage the Senate to ratify the Convention on the Prevention and Punishment of the Crime of Genocide,” Scott wrote in an email. “For the next 19 years, Proxmire kept his promise, giving more than 3,000 speeches on the Senate floor in support of the convention.”

The Wisconsin Democrat gave his last speech on the topic the same day the Senate ratified the treaty: Feb. 19, 1986.

If that’s what it takes to get a climate treaty ratified, Whitehouse might want to consider moving to daily speeches.

The 100th speech is slated for tomorrow around 6 p.m.