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Mitchell Dickau, PhD

@mitchelldickau.bsky.social

4.3K followers 134 following 69 posts

Climate modelling. Temperature overshoot. Remaining carbon budgets. Temporary carbon storage. Effect of climate change on outdoor skating in Canada. Post-doctoral fellow, Concordia University mitchell-dickau.github.io

Posts Replies Media

Mitchell Dickau, PhD @mitchelldickau.bsky.social · 17/08/2026

In 2023, the record wildfire year, 36.32% of grid cells in Canada saw a month or more smoky days.

This figure shows maps of Canada for each year from 2000 to 2023 showing the number of smoky days at each grid cell.

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 17/08/2026

The analysis shows that, comparing 2001-2005 to 2021-2025, 83% of Canada has seen an increase in smoky days. The average increase in smoky days between these two periods was +5.3 days and a large portion of central Canada has seen +10 smokey days.

This figure shows the change in smoky day frequency over Canada.

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 29/06/2026

We find that the additional change in overshoot scenarios relative to baseline scenarios is proportional to the magnitude x duration of overshoot, which is known as the degree-years of overshoot. Interestingly, this proportionality is independent of peak temperature.

A figure showing the relationship between degree-years of overshot (x-axis) and the additional ocean warming caused by overshoot (y-axis). Dozens of faint grey trajectory lines loop upward and to the right, tracing the evolution of this relationship over time in an ensemble of overshoot scenarios. The endpoints of all these trajectories generally land on a single, linear red regression line that extends from the origin, annotated with an R-squared value of 0.996. A horizontal colorbar at the bottom indicates the "Peak temperature reached during overshoot (°C)," ranging from blue (lower peak temperatures) to red (higher peak temperatures). The endpoint dots fall perfectly along the same straight line regardless of their colour, visually demonstrating that long-term additional ocean warming is proportional to the cumulative degree-years of overshoot and independent of the peak temperature reached.

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 29/06/2026

We find that immediately following overshoot, the high-latitudes are warmer while equatorial and mid-latitudes are cooler in overshoot scenarios relative to their respective baselines. Illustrative here by the average reversibility (%) of SAT at each grid cell across the ensemble.

A global map illustrating the average spatial reversibility percentage of Surface Air Temperature (SAT) across a climate model ensemble immediately following a temperature overshoot. A vertical colorbar on the right scales from 80.0% (dark red) to 120.0% (dark blue), with 100.0% represented as white. The map shows a stark regional contrast: high-latitude regions, including the Arctic and Antarctica, are shaded in deep red and orange (below 100%), indicating they remain warmer than the baseline scenario. Meanwhile, low- and mid-latitude regions across the continents and oceans are shaded in light to dark blue (above 100%), indicating they are cooler than the baseline. Black contour lines outline the boundaries between these warming and cooling zones.

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 13/01/2026

Happy to announce that I passed my PhD defence yesterday!! Thanks to my supervisor @damonmatthews.bsky.social and the members of my examining committee — @nadinemengis.bsky.social, @gidden.bsky.social, Kirsten Zickfeld, and Sam Rowan

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 30/04/2025

For global temperature ✅ If we're rapidly cutting emissions, temporary CDR can help reduce peak warming. ⚠️ If emissions stay high past 2100, it only delays the heat—not avoids it.

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 30/04/2025

Just presented some of my ongoing research at #EGU25 in Vienna! A thread...

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 18/11/2024

Given the warming contributions from CO2 and CH4 (in the figure you posted), we know that these are the most important to reduce. But all 1.5 to well-below 2C scenarios (C1, C2, C3) assessed in AR6 see declining CH4 emissions, largely because CH4 is co-emitted along CO2

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Mitchell Dickau, PhD @mitchelldickau.bsky.social · 18/11/2024

Methane is on the rise from biogenic and fossil sources (see the figure below). If the fossil methane emissions were eliminated, the rate of methane emission would decline and so would the warming contribution of non-co2 emissions.

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