Climate Change: Unit Review

The fraction of incoming sunlight a surface reflects, from 0 (absorbs all) to 1 (reflects all).

400 × 0.15 = 60 W/m².

Any three, e.g.: the Sun (energy source); the oceans (store and move heat); the atmosphere (holds greenhouse gases, carries heat by winds); the cryosphere (reflects sunlight); land/topography (steers winds and precipitation); the biosphere (exchanges gases).

Caused by humans.

Q = 2000 × 4.18 × 3.0 = 25 080 J (about 25 kJ).

From the lake toward the land (a lake breeze): the land heats faster, air rises over it, and cooler, denser lake air flows in.

Conduction, convection, radiation; radiation crosses space.

Air in the Hadley cell sinks there, warming and drying, so few clouds form.

To the right.

Ontario lies in the westerlies, and the jet stream steers weather systems from west to east.

500 × 334 = 167 000 J (167 kJ).

It releases energy (latent heat), which warms rising air and powers thunderstorms and hurricanes.

Cold air crossing a large, unfrozen lake picks up heat and moisture. The air rises, forms clouds and drops heavy snow on the downwind shore.

A dry area on the leeward side of mountains, where sinking air is dry and warming.

Temperature and salinity.

The North Atlantic Current carries tropical heat toward Europe and westerly winds blow mild ocean air onto it; Labrador has the cold Labrador Current and winds from the cold continent.

They are often milder than usual, especially in western and central Canada.

D (coldest below −3 °C), f (no dry season), a (warmest ≥ 22 °C): Dfa.

42 ÷ 12 = 3.5 °C.

Hudson Plains, Boreal Shield, Mixedwood Plains.

Two identical atoms can't vibrate in a way that absorbs infrared.

About 33 °C (from about −18 °C to about +15 °C).

Natural: from naturally occurring greenhouse gases and clouds; essential for life. Anthropogenic: extra warming from gases added by humans.

To check consistency, reduce random error, and make sure differences come from the gas, not the position.

Reaction with hydroxyl (OH) in the atmosphere; about 12 years.

4.0 × 28 = 112 t CO₂e.

Roughly half.

Its amount depends on temperature: warming from other gases increases water vapour, which adds more warming.

Any three: volcanic eruptions (1–3 years), solar cycle (11 years), Milankovitch cycles (tens of thousands of years), plate tectonics and weathering (millions of years).

They reflect sunlight and cause cooling (temporary, while they remain in the air).

Its output has been flat or slightly decreasing since the 1950s while Earth warmed quickly.

Past concentrations of CO₂ and methane.

2025 − 95 = 1930.

It stayed between about 180 and 300 ppm naturally; today it is above 420 ppm.

75 ÷ 40 ≈ 1.9 ppm per year.

Two variables can rise together for other reasons. Causation also needs a mechanism, correct timing, fingerprints and other causes ruled out.

We can't experiment on a second Earth; models let scientists compare natural-only and natural-plus-human scenarios and test what-if questions.

It absorbs harmful UV-B and UV-C radiation.

NOx, VOCs, sunlight and heat.

No. Warming is mainly caused by greenhouse gases; ozone depletion is a separate problem (though CFCs are also greenhouse gases).

High health risk; at-risk people should reduce or reschedule strenuous outdoor activity.

Floating sea ice already displaces its weight of water; land ice adds new water to the ocean.

The land is still rebounding after the Ice Age ice sheet melted (glacial isostatic adjustment).

30 × 4.7 = 141 mm ≈ 14 cm (more if the rate keeps increasing).

Positive: longer growing season. Negative: drought, heat stress, new pests, heavy rain and erosion (any one).

Flooding and storm surges contaminate drinking water, spreading diseases such as cholera.

Degradation of dry land so it loses productivity, caused by drought and human land use.

Choosing only the data that support a conclusion and ignoring the rest.

Mainly a values question: it involves trade-offs among jobs, the economy, emissions and the environment, though evidence informs it.

Stop; Investigate the source; Find better coverage; Trace claims to the original.

40–45% below 2005 by 2030; 45–50% below 2005 by 2035 (net zero by 2050).

Any four: emissions impact, scale, cost-effectiveness, speed and durability, fairness, co-benefits and side effects, evidence.

$500 000 ÷ 5000 = $100 per tonne.

It was completed (2014) and produced measurable drops in electricity-sector emissions and smog.