Climate scientist, paleoclimatologist & leaf wax isotope enthusiast at the University of Arizona. Lead Author of the IPCC AR6 WG1 report. Views my own.
Nov 10, 2021 • 9 tweets • 4 min read
I am 🌟thrilled 🌟that this is finally published! Led by my postdoc Matt Osman (no Twitter) let me introduce the first spatial reconstruction of climate changes since the Last Ice Age, the “Last Glacial Maximum Reanalysis”, out today in Nature 1/ nature.com/articles/s4158…
To create the LGMR, we blended info from over 500 geochemical records of sea-surface temperature with climate model simulations using data assimilation. The geological data aren’t evenly spaced in time, so bringing in the model helps us go from point estimates (below) 2/…
Aug 11, 2021 • 14 tweets • 5 min read
One cool part of the #IPCCReport is that it uses not only observations and models to inform climate change but also GEOLOGY, in the form of paleoclimate. Paleoclimate is what I do (!) so naturally, I've got a 🧵 😁 1/
First, what is "paleoclimate"? It is the study of past climate change, over multiple timescales. Could be hundreds of years in the past, could be millions. How do we do this? We measure things in natural archives of past climate change 2/
Aug 9, 2021 • 12 tweets • 4 min read
This has been the news recently, so let's go over what the @IPCC_CH has to say about whether the Gulf Stream will shut down in the coming decades. Short answer: it's not likely to happen. Long answer: keep reading 1/ washingtonpost.com/climate-enviro…
Chapter 9 has an *awesome* FAQ (shout out to @baylorfk ) about this which I encourage you to read. It starts by clarifying what exactly the Gulf Stream is, which is important 2/
Aug 9, 2021 • 10 tweets • 4 min read
The @IPCC_CH report is out, so let's talk about #drought. There are major advances in the report on this. In the last report (8 years ago) scientists weren't sure whether some of the bad droughts we were seeing were caused by humans. Things have changed. 1/
First, what is a #drought? It's complicated! You need low rainfall, but things that "remove" water from land (wind, temperature, evaporation) are also important. In Chapter 8 you'll find a diagram with all these factors. We tried to make it simple, but 🤣 2/
Aug 8, 2021 • 13 tweets • 3 min read
The @IPCC_CH report will be released in the early AM tonight. I helped author it, and tomorrow I'll tweet about some of the findings re: #drought which was one of the things I worked on. In the meantime, it's worthwhile knowing a few things about the process 1/
IPCC authors like myself do not get paid! We volunteer. It's a three year commitment and it becomes a deep part of your life. Why do we do it? Because we care about making sure the world knows about what has happened and what will happen if we don't cut emissions. 2/
Feb 21, 2021 • 6 tweets • 2 min read
So, do you all know who the lead author is of that 42,000-yr climate event Science paper? It's this guy. nature.com/articles/d4158…
This totally fits with the energy of the paper, which makes unsupported claims about both the genetics and paleoclimate data. Here's a great thread about problems with the former
It's #FigureFriday, so let's chat about my favorite subject: color palettes 🎨 for climate science visualization! (1/12)
First, why is it important? Put simply: a beautiful figure can communicate your results more effectively than text. It can make a figure more understandable to a public audience. So it is worth it to put care into your figure design. (2/12)
Nov 5, 2020 • 7 tweets • 5 min read
The timing could be better 🥺 but our major review paper on past climates has just dropped in @ScienceMagazine. In this review, we argue that past climate climates are key to predicting the future 🗝️ science.sciencemag.org/content/370/65…
Our future climate trajectory is still unknown, but it's going to be toasty: comparable to many of the warm climates of the past 100 million years.
Aug 26, 2020 • 6 tweets • 4 min read
Our paper on Last Glacial Maximum (LGM) cooling and climate sensitivity is out today in @nature! This represents four years of work, so it feels really good to see it released. Here's a short thread on what it means... nature.com/articles/s4158…
First we compile almost 2,000 geological measurements of sea-surface temperature, which believe me took some time! Then, we ran new simulations of the LGM with the @NCAR_Science CESM model, and used data assimilation to combine the info. This gives us global maps of temperature!
Jan 3, 2019 • 7 tweets • 3 min read
While there is certainly nothing wrong with making individual low-carbon choices, I am increasingly concerned with how the #actonclimate movement is emphasizing individual lifestyle over collective action. There are two problems with this (thread).
One is that framing the issue in terms of lifestyle carries with it the race/class/health/wealth point of view of the framer. But not everyone's relationship with #climatechange is the same. This was the major critique of late 20th century environmentalism hcn.org/issues/42.2/th…
