Climate Futures

— the warming scenarios, in plain language

This page explains what the world’s climate scientists actually say is happening and where it’s heading — not a worst-case headline, not a reassurance. Every figure below carries the date it was measured or published.

What’s actually happening

2024 was the warmest year in the instrumental record — the first calendar year to average more than 1.5°C above the 1850–1900 baseline used to measure “before industrialization” (Copernicus, the EU’s climate monitoring service, puts it at roughly 1.60°C). 2025 came in as the third-hottest year on record, at about 1.47°C (Copernicus) or 1.43°C (the World Meteorological Organization’s own separate measure) — the small gap between two respected trackers is itself a useful fact: even “the global temperature” carries real, honestly reported measurement uncertainty. June 2026, the most recent month with published data (released July 9, 2026), was 1.39°C above pre-industrial levels, the second-warmest June on record.

This matters: the Paris Agreement’s 1.5°C goal is about sustained warming averaged over decades, not any single year. Copernicus’s own reporting states current sustained warming is closer to 1.4°C. A hot year passing 1.5°C is real evidence of where the trend is heading; it is not the same as saying the Paris target has already been missed.

Climate Action Tracker, an independent group that reviews what governments are actually doing (not just promising), found in its most recent update (November 13, 2025) that warming under today’s current policies — the laws and programs actually in place — points to about 2.6°C by 2100. If every country fully delivers on its stated pledges, that falls to about 2.2°C; if every announced net-zero target is also met, about 1.9°C. The tracker’s own framing: the last four years have shown “little change in warming outlook” — the faster progress right after the 2015 Paris Agreement has largely flattened out.

Climate costs are already showing up in insurance data, not just projections. 2024 was the costliest year in Canadian history for insured severe-weather losses, at roughly $8.55 billion — nearly triple 2023’s total and about 12 times the 2001–2010 annual average. A single event drove much of that: the July 15–16, 2024 flash flood across Toronto and the Greater Toronto Area caused an estimated $990 million in insured damage on its own. 2025’s national total came in lower, at just over $2.4 billion — a reminder that any single year, in either direction, reflects real weather variability, and it’s the multi-year pattern that carries the signal.

Where credible people think it’s heading

Climate scientists use five scenario families — called SSPs — to explore a range of possible futures, not to predict one. They come with no attached probability. The Intergovernmental Panel on Climate Change’s own 2021 assessment gives a best-estimate warming outcome for each by 2081–2100: the lowest-emissions pathway lands around 1.4°C; the “middle of the road” pathway around 2.7°C; the highest-emissions pathway around 4.4°C. Today’s real current-policy trajectory (about 2.6°C, above) sits much closer to the middle pathway than to the high one, even though the high one is still sometimes invoked in headlines as “business as usual.”

On tipping points — thresholds past which a change in the climate system could become hard to reverse — two credible but differently built assessments currently give different pictures, and neither is simply wrong. The IPCC’s 2021 assessment, built on evidence available through around 2021, uses cautious language: it states there is “medium confidence” that an ocean current system called the AMOC (which partly regulates Western European and eastern-Canadian winters) will not collapse abruptly before 2100. The Global Tipping Points Report 2025 — a newer, faster-moving assessment from about 160 scientists across 87 institutions, not yet run through the IPCC’s own review process — argues warm-water coral reefs have a central tipping-point estimate around 1.2°C, meaning today’s roughly 1.4°C of warming may already be past it, and that reefs are “virtually certain” to tip even if warming holds at 1.5°C. One is a slower, government-negotiated consensus text; the other is a faster synthesis of newer research. Both are named and dated here rather than one being picked as right.

What’s honestly uncertain

The IPCC’s next full assessment (AR7) has been delayed by what one climate-journalism outlet calls “unprecedented” gridlock among governments over its own production timeline; the report meant to pull all its findings together is now targeted for release by late 2029. The next authoritative update to the picture above is genuinely years away.

Sea-level rise is well-projected to 2100 (a likely range of roughly 0.28–0.55 metres under the lowest-emissions pathway versus 0.63–1.02 metres under the highest, relative to 1995–2014) but far less certain beyond that: the physics of ice sheets in West Antarctica and Greenland are not yet well-constrained by current models, meaning the “worst case, centuries out” is wider than the 2100 number implies.

Why it matters for Toronto

A report prepared for the City of Toronto (posted December 2024) projects the city’s number of days per year above 30°C rising from a 1980s baseline of roughly 10 days to about 24 days by the 2080s under a medium-emissions pathway (flagged honestly: this is the one figure on this page our re-verification pass could not independently confirm — it sits in a table of the City’s PDF that resists text extraction; the surrounding figures in the same report re-verified exactly) — or by more than two additional months of such days under a very-high-emissions pathway. Annual precipitation is projected up 11–16% by the 2080s, with extreme one-day rainfall events — the kind that cause basement and expressway flooding — up an estimated 18–27% over the same period. Ontario’s own provincial climate assessment (completed January 2023, made public about eight months later after no formal announcement) separately projects southern Ontario reaching 55–60 days per year above 30°C by the 2080s under a high-emissions pathway — more than triple today’s roughly 16 such days — and flags potential corn-yield declines of up to 50% in parts of the province.