Five hundred years of watching

England ran short of firewood before it ran short of anything else. Historians estimate coal shipped from the Tyne to London grew from a few tens of thousands of tons a year in the 1550s to roughly half a million by the 1690s — a fuel switch made not out of ambition but out of scarcity. That switch is still running. Coal took about two centuries to climb from a sliver of world energy to half of it.

The paradox worth sitting with: the cheapest electricity in human history now exists, and fossil share has barely moved, because total demand keeps climbing. Addition is not substitution. The 500-year record says energy systems change over 50–100 years; the physics says this one has about 25.

• NOAA CO₂ trends
• OWID Energy
• IEA WEO 2024
• Statistical Review of World Energy

Roughly 500 million people in 1500. One billion around 1804. Two billion by 1927. Eight billion on 15 November 2022. For five centuries every pension, army, church, city plan and business model quietly assumed there would be more of us next year. That assumption is expiring inside this century.

Japan recorded its fewest births since national records began in 1899. Meanwhile more than half of all births after 2050 are projected in sub-Saharan Africa. This is not one demographic story; it is two opposite ones happening at once, and almost every institution is designed for neither.

• UN World Population Prospects
• OWID Population
• Gapminder

The IUCN uses 1500 as its extinction baseline — the same starting line as this page. Since then it documents more than 900 species gone, and that is only what we watched closely enough to record. The passenger pigeon darkened North American skies in flocks of billions; the last one died in a Cincinnati cage in 1914. Abundance collapsed long before the species did.

That last figure is the one that reorders your sense of the planet. By weight, wild mammals are a rounding error on a world of cattle, pigs and people. The question for the next century is not only what survives, but whether abundance — the sky full of birds, the windscreen full of insects — can be deliberately rebuilt.

• IUCN Red List
• Living Planet Report
• Hallmann et al. 2017
• Bar-On et al. 2018, biomass of Earth

In 1909 Fritz Haber pulled nitrogen out of the air in a laboratory; by 1913 it was industrial. Roughly half the nitrogen atoms in your body passed through that reaction. It is arguably the single most consequential chemistry of the last 500 years — it fed billions, and it also runs off into rivers and coastal dead zones. Medieval English wheat yielded well under a tonne per hectare. Today it is around eight.

Abundance built on aquifers filled over millennia and topsoil built at roughly a centimetre per century is not income. It is a withdrawal. The honest accounting question is whether a field, a watershed, a delta is being farmed at its rate of renewal — and almost nowhere is that number on the balance sheet.

• Erisman et al., a century of ammonia
• Rodell et al. 2009, India groundwater
• FAOSTAT

Within fifty years of Gutenberg, Europe printed an estimated 20 million volumes — more books in half a century than its scribes had copied in the previous thousand years. What followed was not instant enlightenment. It was a century of religious war, and witch-hunting that peaked between roughly 1560 and 1630, propelled by cheap printed manuals. New information technology amplifies conflict first and settles truth much later.

We are one or two generations into a technology that can manufacture plausible record at zero marginal cost. The 500-year lesson is that societies eventually built the institutions that made print trustworthy — libraries, citation, peer review, the press. Those took two centuries. We are asking for them in twenty years.

• ITU Facts & Figures
• OWID Internet

Start with the good news, because it is enormous and often forgotten: global life expectancy sat near 30 years for most of the last five centuries and is now over 73. Child mortality fell from roughly one in two to under one in twenty. Whatever else the record shows, it shows that deliberate, boring, funded work — vaccines, sanitation, midwives — moves the biggest numbers there are.

The mismatch is structural, not moral. Quarterly earnings and election cycles are excellent instruments for short problems and useless for slow ones. Yet long institutions have existed: Venice managed oak forests for centuries to keep its shipyard alive; the Haudenosaunee principle asks what a decision does to the seventh generation. Precedent exists. It is simply not the default.

• OWID Life Expectancy
• World Inequality Report
• IPCC AR6 Synthesis

Cologne Cathedral was begun in 1248 and completed in 1880 — 632 years, generations of masons working to drawings they would never see raised. That capacity has not disappeared. In Finland, Onkalo is being built to hold spent nuclear fuel securely for 100,000 years, the first repository of its kind. In Svalbard, a vault holds over 1.3 million seed samples; in 2015 researchers displaced by the war in Syria made the first withdrawal, and it worked.

Every one of the six questions above eventually reduces to this one. Not what do we believe, but what have we built that outlives our attention span — a forest, an archive, an endowment, a repaired soil, a trained successor. The next hundred years will be measured in handovers.

• Posiva · Onkalo
• Svalbard Global Seed Vault
• The Long Now Foundation