Background

Climate change has been a prominent media topic for several decades; most students are likely aware that it is caused by emissions from continuous burning of fossil fuels, and of the imminent dangers it presents. Reducing or eliminating emissions is an obvious mitigation exercise, but is that enough? Do we also need to remove the existing emissions from the environment, and how can we do that?

In this program, students learn through experimentation the science behind the enhanced greenhouse effect, ocean acidification, and other ways excess carbon dioxide impacts the environment and climate. They then investigate a promising method for removing excess carbon from the ocean, by harnessing the natural potential of macroalgae, and explore why this is particularly effective.

Prior Knowledge

Some knowledge of the electromagnetic spectrum, acid/base chemistry and photosynthesis is recommended, but not essential.

Learning Intentions

In this program, students will:

• Discover how CO₂ in the atmosphere interacts with solar radiation to produce the greenhouse effect, and its contribution to climate change
• Investigate how the interaction of the atmosphere with the hydrosphere leads to ocean acidification
• Understand the potential for macroalgae to remove large quantities of excess CO₂ from the oceans
• Gain a sense of optimism that there are technological solutions to the growing global problems

Activities

Students will:

• Use thermal imaging cameras to measure how CO₂ interacts with infrared radiation
• Perform experiments to explore the chemistry of CO₂ and water
• Discover how effectively algae can sequester carbon dioxide from the atmosphere and thus aid in mitigating climate change
• Investigate the spectral absorbance of the pigments in algae that makes it particularly effective in photosynthesising

VCE links

Major factors that affect Earth’s climate

• The interactions between solar energy that is absorbed, re-emitted and reflected by atmospheric gases and other matter, including the albedo effect, the natural greenhouse effect, and ocean circulation.
• Carbon sequestration in land and water that results in short-term (less than 100 years) and long-term (more than 1000 years) changes in the carbon cycle.

Understanding climate change

• The differences between natural and enhanced greenhouse effects.
• Altered greenhouse gas concentrations over different time periods – seasons, years, centuries and millennia – due to natural events, and human activities associated with the combustion of fossil fuels, cement production, agriculture and land use changes.
• Greenhouse gas warming potential as a measure of the infrared radiation the gas will tend to absorb over its lifetime in the atmosphere.

Managing climate change

• The risks and opportunities associated with climate change for humans and ecological systems at a selected region or location: increase in range of exotic species; changes in length of plant growing seasons and animal breeding cycles; phenological changes for plant-pollinator interactions; increasing risks to coastal infrastructure from continuing sea level rise; reduction in agricultural production due to warmer and drier conditions.
• Mitigation options for reducing net greenhouse emissions to slow climate change.
• Interconnections and tensions between factors that influence responsible decision-making around managing climate change: diverse stakeholder values, knowledge and priorities, regulatory frameworks that inform environmental management strategies, use and interpretation of historical and current scientific data, and application of new technologies.