8/6/2019 Learning about Biodiversity March 2011 Page 2

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CLIMATE CHANGE

Climate change is not a new phenomenon. The earth’s climate has changed – warmedand cooled – or millions o years. The dierence between past uctuations and thewarming currently under way is that human activities are speeding up the process, sothe eects o climate change are happening rapidly. Such rapid climate change posesproblems to both people and wildlie, as both try to cope with the changes.

Analyses o ice cores, corals, tree rings and historical weather records indicate that

the period between 1990-2000 was the warmest decade o the last millennium.Eleven o the last 12 years rank among the hottest years since 1850, when records o global surace temperatures began.

The major consequences o climate change will be:

Sea level rise: This is partly caused by the melting o the polar ice caps, but mostly by the simple expansiono water as it heats up. Coastal environments cover a mere 20% o the earth’s surace, yet they produce aquarter o our global biological diversity.

Inability of species to adapt: The rate o change may be so rapid that species adapted over millions o years to living in extreme heat, cold, altitude or specialist environments (such as cloud orest or high snowymountains) may not be able to adjust their behaviour (such as breeding, eeding or timing o migration

 journeys) quickly enough, and may die out altogether.

Unpredictable seasons: The world’s weather patterns are extremely complex and interdependent. Onechange may lead to another, and another, and the delicate balance may become irrevocably upset. Severestorms and huge wildfres are also becoming more common around the world, while the world’s watersupply is threatened and agricultural yield is decreasing.

What can we do?Humans are pumping carbon and other greenhouse gases into the atmosphere. Greenhouse gases changethe way in which energy rom the sun enters and escapes rom the atmosphere. This is changing the balanceo incoming and outgoing heat by trapping more o the outgoing heat. Higher average temperatures on theearth’s surace are causing a change in worldwide weather patterns. We have already seen the average annualglobal temperature reach a record high in 2005. These eects are set to get worse, unless we take action now.

Adaptation and Mitigation

There are generally two approaches to fghting climate change: adaptation and mitigation. The adaptation approach looks at measures toprepare or and respond to climate change by adapting systems, services, inrastructure and practices. The mitigation approach takes mattersurther, and reduces the human contribution to climate change, or example by releasing less CO

²into the atmosphere.

Prevention is always better than cure – it is much cheaper and more eective in the long run to prevent climate change than to try toadapt to it. We need to strike a balance between the two and address both adaptation and mitigation. For example, by insulating roos innew housing, we will be adapting these houses to deal with higher or lower temperature extremes, while also mitigating climate change byreducing the energy needed or indoor heating or cooling.

CURRICULUM-BASED ACTIVITIES

Interview some adults in your community to fnd out how things have changed in their lietime. I you eel that things have changed or theworst, or example, there are no more trees where your grandmother remembered trees once growing, write a letter to your local newspaper orto an important politician who you eel might be interested. Explain the inormationthat you have gathered, and why you think that something should be done to tryand adapt or prevent the situation rom worsening. Remember to ask or a reply!

Outcomes 

Languages – listening: The learner is able to listen or inormation and enjoyment,and respond appropriately and critically in a wide range o situations.Languages – speaking: The learner is able to communicate confdently andeectively in a spoken language in a wide range o situations.Arts and Culture expressing and communicating: The learner is able to analyzeand use multiple orms o communication and expression.

In the case o climate change, or ‘global warming’ both the causesand eects are international. I the most moderate predictions madeby scientists about the eects o climate change are correct, there isno country that will not be aected. Some changes are already easy

to see and experience – in already drought-prone countries, droughtsare becoming longer and hotter, and rainy seasons have becomeerratic and unpredictable. Rain and wind storms are becoming morerequent and many unusual weather events have been recorded.

What eects will climate change have?

This act sheet is adapted by kind courtesy o BirdLie South Arica (BLSA) and the City o CapeTown’s Environmental Resource ManagementDepartment. Visit them at www.birdlie.org.za andwww.capetown.gov.za/environment.

LEARNING ABOUT BIODIVERISTY

 VELD&FLORA  | MARCH 201124