Dan Simmons’ Facebook comment mocking teenaged environmental activist Greta Thunberg, who recently spoke at the U.N., is now removed, however, screencaps were shared and many sff writers and fans have tweeted their dismay.

Simmons is a World Horror Grandmaster and past winner of the Hugo (for Hyperion), World Fantasy Award, Bram Stoker Award, British Fantasy Award and Theodore Sturgeon Memorial Award.

Here is a full screencap.

Here is a sampling of the reaction.

Jeff VanderMeer

Wow. Nice one, Dan Simmons. What a jerk. pic.twitter.com/6VKCFPvU6a — Jeff VanderMeer (@jeffvandermeer) September 25, 2019

Stina Leicht

No more Dan Simmons for me. — Stina Leicht (@StinaLeicht) September 25, 2019

Ilana C. Myer

Shut up, Dan Simmons. — Ilana C. Myer (@IlanaCT) September 25, 2019

Adam-Troy Castro

Gently: there is a reason I love most of Dan Simmons's books, but stay the hell away from his social media. — adam-troy castro (@adamtroycastro) September 25, 2019

Paul Tremblay

Just in case you needed a reminder, Dan Simmons is a jerk. pic.twitter.com/m8PnfaTozQ — Paul Tremblay (@paulGtremblay) September 25, 2019

Robin Johnson (the game developer, not the Australian fan)

@midnight_pals Dan Simmons: I have a story about something VERY scary

King: Go on

Simmons: It's utterly terrifying

King: Ok, whenever you're ready

Simmons: For the approval of the Midnight Society, I call this story

Simmons: The Tiny Autistic Girl

Lovecraft: AAAAAAAAAAHH — Robin Johnson (@rdouglasjohnson) September 25, 2019

Sarah Pinborough

Very sad to see Dan Simmons comments on Greta Thunberg on Facebook. But not for Greta, who's clearly a powerhouse, but for a 71 year old white man who can't see that maybe we should listen to youth when it comes to saving the planet and wants to call her 'bratty'. — Sarah Pinborough (is working but will be back) (@SarahPinborough) September 25, 2019

Richard Webb

Thoughts and prayers for Dan Simmons’ publicist. — Richard Webb (@RaW_writing) September 25, 2019

April A. Taylor

So disappointed by Dan Simmons (author of The Terror, etc.) & his long-winded rant against Greta Thunberg. If you're a successful 71-year-old man who is so threatened by a 16-year-old girl on the spectrum that you publicly bash her, then the problem is clearly with you, not her. https://t.co/gtPKQvlvba — April A. Taylor (@aprilataylor) September 25, 2019

Paul Weimer

Oh, Dan Simmons jumped the shark with me with the Islamophobia that came out nowhere in OLYMPOS, plus a "thought experiment" on his blog that really went into the Eurabia stupidity. — Paul Weimer ? (@PrinceJvstin) September 25, 2019

Ellen Datlow

I published his early work and considered him a friend-I spent time with him and his family in the 80s/90s. Lost touch mostly but in the last few years had heard he'd turned right, into someone I wouldn't recognize. — Ellen Datlow (@EllenDatlow) September 25, 2019

Laird Barron (in a public Facebook comment)