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| Line 2,333: |
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| | colspan="1" |0 | | | colspan="1" |0 |
| |worldwide acceleration of glacier melt, now at twice the speed of 20 years ago → explaining one-fifth of the rate and acceleration in sea-level rise during the 21ˢᵗ century | | |worldwide acceleration of glacier melt, now at twice the speed of 20 years ago → explaining one-fifth of the rate and acceleration in sea-level rise during the 21ˢᵗ century |
| |-
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| | colspan="1" |2021
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| | colspan="1" |0
| |
| |human activities have unequivocally warmed atmosphere, ocean and land, intensifying heatwaves, floods and droughts; global warming will exceed 2°C without immediate, rapid and large-scale reductions in greenhouse-gas emissions (IPCC, 2021): a reality check for policy makers
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| |- | | |- |
| | colspan="1" |2021 | | | colspan="1" |2021 |
| Line 2,342: |
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| |Earth’s hottest month on record (NOAA, July 2021): rising frequency of climate anomalies | | |Earth’s hottest month on record (NOAA, July 2021): rising frequency of climate anomalies |
| |} | | |} |
| {| class="wikitable"
| | ''You made it! Look whats been going on for the past few years...'' |
| | colspan="1" |'''Ages''': following the big bang 13.8 billion years ago, time passed two-thirds of the way to the present before the formation of the Sun 4.57 billion years ago. Rescaled to a calendar year, starting with the big bang at 00:00:00 on 1 January (), the Sun forms on 1 September (), the Earth on 2 September (), earliest signs of life appear on 13 September (), earliest true mammals on 26 December (), and humans just 2 hours before year’s end (). For a year that starts with the earliest true mammals (), the dinosaurs go extinct on 17 August (), earliest primates appear on 9 September (), and humans at dawn of 25 December (). For a year that starts with the earliest humans (), our own species appears on 19 November (), the first built constructions on 8 December (), and agricultural farming begins at midday on 29 December ().
| |
| | |
| '''Quantities''': 1 thousand = 10³ = 10×10×10 = 1,000; 1 million = 10⁶; 1 billion = 10⁹; 1 trillion = 10¹².
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| | |
| '''Units''': metre (m); kilometre (km); hectare (ha); kilogramme (kg); kilowatt-hour (kWh).
| |
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| '''Distances''': 10⁹ nanometres in 1 m; 1,000 m in 1 km; 9.46 trillion km in 1 light-year. ''For example'': 0.1-nanometre diameter of a hydrogen atom; 40,000-km circumference of Earth; 150 million km from Earth to the Sun; 300,000 km travelled by light in 1 second, and almost 10 trillion km in 1 year; 27 thousand light-years from Earth to the Galactic Center of the Milky Way; 46.5 billion light-years from Earth to the edge of the observable Univer
| |
| | |
| '''Volumes''': 1 billion m³ in 1 km³; 1 trillion m³ in 1,000 km³. ''For example'': 1 billion grains in 1 m³ of sand; 2.5 trillion m³ (2,500 km³) of water in Lake Victoria.
| |
| | |
| '''Masses''': 1,000 g in 1 kg; 1,000 kg in 1 tonne. ''For example'': 100-tonne mass of a blue whale; 500 million tonnes of global human biomass.
| |
| | |
| '''Power and energy''': 1 watt of power uses 1 joule of energy per second; about 740 watts in 1 horsepower; 3,600 kilojoules (kJ) or 860 kilocalories (kcal) in 1 kWh of energy, sustaining 1,000 watts for 1 hour. ''For example'', a 100-watt incandescent light bulb illuminates a room; 80 watts sustain human basal metabolic rate, using 6,900 kJ or 1,650 kcal or 1.92 kWh of energy per day; rice and maize have an energy value per kg of 15,280 kJ or 3,650 kcal or 4.25 kWh, wheat has nine-tenths this energy, and beef has two-thirds; crude oil and natural gas provide a heat value per kg of about 45,000 kJ or 10,750 kcal or 12.5 kWh, coal gives nearly half this heat, and firewood one third. | |
| | |
| '''Information sources''': inline links, ''Wikipedia'', ''Encyclopaedia Britannica'', BBC.
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| | |
| '''Inspiration''': “It is the stars, the stars above us govern our conditions” William Shakespeare, ''King Lear'' (1608). “Das ewig Unbegreifliche an der Welt ist ihre Begreiflichkeit [The eternal mystery of the world is its comprehensibility]” Albert Einstein (1936).
| |
| |}
| |
| {| class="wikitable"
| |
| |C. Patrick Doncaster, 23 October 2021, one of the then 7,797,895,910 (rising by 151 per minute, 79 million per year)
| |
| |}
| |
| References
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|
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|
| | === References === |
| 1 https://www.science.org/doi/10.1126/sciadv.abc0776 | | 1 https://www.science.org/doi/10.1126/sciadv.abc0776 |