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A2.2 · Identify scientists, including Canadians, and their contributions

Learn to identify scientists, including canadians, and their contributions through clear examples and targeted practice.

Ontario Grade 10 Science

Scientific Investigation and Careers

SNC2D A2.2: Identify scientists, including Canadians, and their contributions

A clear greenhouse can feel warmer than the air outside. That everyday observation does not, by itself, explain Earth’s climate. Over time, scientists used experiments, measurements, and models to investigate how the atmosphere affects temperature. In this lesson, you will meet several scientists whose contributions helped build that understanding, including Canadian scientists. The focus is not on memorizing dates. It is on connecting each scientist to the evidence or idea they contributed.

What you will learn

Identify scientists who helped build knowledge about the greenhouse effect and climate change.
Describe each scientist’s contribution in clear, accurate terms.
Explain how observations and evidence helped scientists improve their understanding.
Distinguish the natural greenhouse effect from its human-driven enhancement.

1. From an observation to a scientific question

In Grade 9, you learned that observations are information gathered using senses or tools. An observation can lead to a question. For example, if a greenhouse feels warmer than its surroundings, you might ask what causes the temperature difference.

Earth also has a natural greenhouse effect. Some gases in the atmosphere absorb and release energy, which helps keep the planet warm enough for life as we know it. This natural effect is different from its human-driven enhancement. Human activities, especially burning fossil fuels, have increased the amount of some heat-trapping gases in the atmosphere. The added gases strengthen the natural effect and contribute to climate change.

Scientists did not all study the same part of this story. Some investigated how gases interact with energy. Others estimated how changes in atmospheric gases could affect temperature. Later scientists measured atmospheric carbon dioxide over time or used climate models to study future conditions. A climate model is a computer-based representation used to explore how parts of the climate system may behave.

An observation can lead to a testable scientific question.
The natural greenhouse effect is not the same as its human-driven enhancement.
Scientific understanding grows through different contributions over time.

2. Scientists who built the evidence

In 1856, American scientist Eunice Foote reported an experiment using glass cylinders containing different gases. She found that cylinders containing moist air and carbon dioxide warmed more in sunlight than cylinders containing ordinary air. Her work was an early investigation of how gases could affect heating. It was not a complete explanation of Earth’s climate, and she did not measure the modern rise in atmospheric carbon dioxide.

In 1859, Irish physicist John Tyndall measured how gases absorbed radiant heat, including heat that people cannot see. He showed that gases such as water vapour and carbon dioxide absorb this energy differently from gases such as oxygen and nitrogen. This helped explain why small amounts of certain gases can matter to the atmosphere’s warming.

In 1896, Swedish scientist Svante Arrhenius estimated how changes in atmospheric carbon dioxide could affect Earth’s temperature. His work connected the gas’s properties to a possible change in global temperature. His estimate was an early calculation, not a modern climate projection.

In 1958, American scientist Charles David Keeling began precise, continuous measurements of atmospheric carbon dioxide at Mauna Loa in Hawaii. The measurements showed a repeating seasonal rise and fall, along with a longer-term upward trend. This record became important evidence that atmospheric carbon dioxide was increasing.

Foote investigated how gases warmed in sunlight.
Tyndall measured how gases absorbed radiant heat.
Arrhenius estimated how changing carbon dioxide could affect temperature.
Keeling’s measurements revealed seasonal changes and a longer-term rise in atmospheric carbon dioxide.

3. Canadian contributions and the role of models

Canadian-born climate scientist Katharine Hayhoe studies how climate change may affect different places and communities. She has contributed to climate assessments, including reports of the Intergovernmental Panel on Climate Change, an international group that assesses climate research. Her work helps connect climate science with questions about regional impacts.

Canadian climate scientist Andrew Weaver has contributed to climate modelling and to assessments of climate science. A climate model represents parts of the climate system so researchers can examine how conditions may change under different assumptions. Models are not direct observations of the future. Scientists compare their results with observations and explain the limits of the models.

These examples show different kinds of contribution. Foote and Tyndall investigated how gases interact with energy. Arrhenius used those ideas to estimate a possible temperature effect. Keeling produced a long record of measurements. Hayhoe and Weaver have contributed to later climate research and assessment. Together, these contributions help explain how scientific knowledge is built and checked.

Katharine Hayhoe and Andrew Weaver are Canadian climate scientists.
A contribution may involve experiments, measurements, calculations, modelling, or assessment.
Models help explore climate questions, but they are not observations of the future.

4. Reading evidence carefully

When identifying a scientist’s contribution, name what the scientist did and what the work helped people understand. Avoid saying that one scientist alone discovered or proved the whole modern explanation of climate change. Knowledge developed through many studies, and later evidence refined earlier ideas.

A useful way to read a scientific claim is to ask: What was observed or measured? What conclusion did the evidence support? What did the evidence not establish? For example, Keeling’s record showed that measured atmospheric carbon dioxide rose over time. That record alone is not every part of the evidence for climate change, but it is an important measurement that scientists can compare with other evidence.

Historical experiments and modern measurements are not the same kind of evidence. Foote’s experiment helped investigate gas heating under particular conditions. Keeling’s measurements tracked atmospheric carbon dioxide at a location over many years. Both are valuable, but each answers a different question.

Match each scientist with a specific contribution.
State what the evidence supports without claiming more than it shows.
Different types of evidence answer different scientific questions.

Scientists and contributions

Scientist	Contribution
Eunice Foote	Investigated how moist air and carbon dioxide warmed in sunlight in a cylinder experiment.
John Tyndall	Measured how gases, including carbon dioxide and water vapour, absorbed radiant heat.
Svante Arrhenius	Estimated how changes in atmospheric carbon dioxide could affect Earth’s temperature.
Charles David Keeling	Began precise, continuous atmospheric carbon dioxide measurements that showed seasonal variation and a longer-term rise.
Katharine Hayhoe	Canadian-born climate scientist who studies climate impacts and has contributed to international climate assessments.
Andrew Weaver	Canadian climate scientist who has contributed to climate modelling and climate assessments.

Worked example

Match a scientist to the contribution

A class has four contribution cards: investigating gas heating in cylinders, measuring heat absorption by gases, estimating a temperature effect from changing carbon dioxide, and recording atmospheric carbon dioxide over many years. Match each card to Foote, Tyndall, Arrhenius, or Keeling.

Look for the type of evidence
A cylinder experiment points to an investigation of gas heating. A long record of atmospheric measurements points to monitoring over time.
Match the contributions
Foote investigated gas heating in cylinders. Tyndall measured heat absorption by gases. Arrhenius estimated a temperature effect from changing carbon dioxide. Keeling began precise, continuous atmospheric carbon dioxide measurements.
Check the scope
Each match names a contribution without suggesting that one scientist completed the whole explanation of climate change.

Answer: Foote: gas-heating experiment; Tyndall: gas absorption of radiant heat; Arrhenius: estimated temperature effects of changing carbon dioxide; Keeling: long-term atmospheric carbon dioxide measurements.

Check: The matches distinguish experiments, measurements, and estimates rather than treating them as the same kind of evidence.

Worked example

Interpret a hypothetical measurement record

Hypothetical data show that atmospheric carbon dioxide measured at one location rises over several decades, while values still rise and fall with the seasons. Which scientist’s contribution does this most closely resemble, and what can the record support?

Identify the evidence type
The information is a set of repeated measurements made over time, not an experiment with different gases.
Connect the record to a scientist
This most closely resembles Charles David Keeling’s contribution: precise, continuous atmospheric carbon dioxide measurements that revealed seasonal variation and a longer-term rise.
State a careful conclusion
The hypothetical record supports the claim that measured carbon dioxide rose over the stated period and varied by season. It does not, by itself, describe every cause or effect of climate change.

Answer: It resembles Keeling’s long-term measurement record. It supports a claim about the measured rise and seasonal variation, but not a complete explanation of climate change on its own.

Check: The data are explicitly hypothetical, and the conclusion does not go beyond what those measurements show.

Worked example

Explain a Canadian scientist’s contribution

A student writes, “Katharine Hayhoe proved exactly what the climate will be in every Canadian community.” Improve the statement so it accurately describes her contribution and the role of climate assessments.

Find the overstatement
The original sentence treats assessments as exact predictions for every community. That is stronger than the contribution described here.
Use an accurate contribution
Hayhoe is a Canadian-born climate scientist who studies climate impacts and has contributed to international climate assessments.
Describe the work carefully
An assessment brings together scientific research to describe evidence and possible impacts. It does not give a certain, exact outcome for every place.

Answer: Katharine Hayhoe is a Canadian-born climate scientist who studies climate impacts and has contributed to international climate assessments. These assessments summarize evidence about possible impacts; they do not state an exact, certain future for every community.

Check: The revision identifies her contribution without presenting climate assessments as perfect predictions.

Common mistakes and how to avoid them

Saying the natural greenhouse effect is the same thing as human-caused climate change.

Correction: The natural greenhouse effect helps warm Earth. Human activities enhance that effect by increasing some heat-trapping gases.

Claiming one scientist discovered the entire modern explanation of climate change.

Correction: Describe each scientist’s specific contribution. Scientific understanding developed through many people’s evidence and ideas.

Treating a climate model as a direct observation or a perfectly certain forecast.

Correction: A model represents parts of the climate system and is used to explore possible changes. It should be considered alongside observations and its limits.

Saying Keeling’s measurements alone explain every cause and effect of climate change.

Correction: His measurements provided important evidence of rising atmospheric carbon dioxide. A broader explanation draws on many kinds of evidence.

Lesson summary

Foote investigated how gases warmed in sunlight; Tyndall measured how gases absorbed radiant heat.
Arrhenius estimated how changing atmospheric carbon dioxide could affect temperature.
Keeling’s long-term measurements revealed seasonal changes and a longer-term rise in atmospheric carbon dioxide.
Canadian scientists Katharine Hayhoe and Andrew Weaver have contributed to climate research and assessment.
Describe what each contribution shows, and do not claim it proves more than the evidence supports.

Check your understanding

Question 1

Which scientist is best known here for beginning precise, continuous measurements of atmospheric carbon dioxide at Mauna Loa?

Eunice Foote
Charles David Keeling
Svante Arrhenius
Andrew Weaver

Show answer and explanation

Charles David Keeling

Keeling began the measurements in 1958. The record showed seasonal variation and a longer-term rise.

Question 2

What is the most accurate description of the relationship between the natural greenhouse effect and its human-driven enhancement?

They are unrelated processes.
The natural effect warms Earth, and increased heat-trapping gases from human activities strengthen it.
The natural effect began only after industrial activity increased.
The human-driven enhancement means that no natural greenhouse effect exists.

Show answer and explanation

The natural effect warms Earth, and increased heat-trapping gases from human activities strengthen it.

The natural greenhouse effect exists without human activity. Human-driven increases in some gases enhance it.

Question 3

Which statement describes Katharine Hayhoe’s contribution most accurately?

She began Keeling’s atmospheric carbon dioxide measurements.
She measured how gases absorb radiant heat in the nineteenth century.
She is a Canadian-born climate scientist who studies climate impacts and has contributed to climate assessments.
She proved the exact future climate of every community.

Show answer and explanation

She is a Canadian-born climate scientist who studies climate impacts and has contributed to climate assessments.

This identifies her work without overstating what a climate assessment can establish.

Key terms

Observation: Information gathered using senses or tools.
Radiant heat: Energy that travels as radiation; some of it cannot be seen by human eyes.
Climate model: A computer-based representation used to explore how parts of the climate system may behave.
Climate assessment: A review that brings together scientific research to describe evidence and possible impacts.

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Published by DoAssignment. This reviewed lesson follows Ontario Grade 10 Science (SNC2D), expectation A2.2. It is a study resource, not an official curriculum publication.

Before publication, content is checked for structure, mathematical or chemical notation, calculations, course boundaries, and readability. Errors can still occur, so corrections are welcomed.

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