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IBDP Biology SL Activity

EVALUATING CLIMATE CHANGEThere have been wide ranging claims about the evidence for and against climate change. This activity aims to provide a structure for evaluating these claims in a scientific way.

This image illustrates one of the arguments which have been used against the evidence for climate change, the idea that scientists don’t agree on the extent of climate change.

This argument is really misleading as the vast majority of scientists agree that the Earth’s temperature is rising, their differences are in the precise details of the climate models used.

Activity 1: where do you stand on climate change?Record your opinion about the evidence in the table by ticking the most suitable answer in each row.

Possible Scientific evidence and explanations of climate change

I am sure this is right

I think this is right

I think this is wrong

I am sure this is wrong

The amount of carbon dioxide in the atmosphere is rising:

Since pre-industrial times, carbon dioxide levels have increased 40 per cent.

The Earth's surface is warming:

Between 1880 and 2012, Earth's surface has warmed by approximately 0.85°C.

Image: NASA Climate 365 go.nasa.gov/climate365

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IBDP Biology SL Activity

Possible Scientific evidence and explanations of climate change

I am sure this is right

I think this is right

I think this is wrong

I am sure this is wrong

Arctic sea ice is melting:

Sea ice extent - has shrunk by between 3.5 and4.1 per cent per decade since 1979Earth's surface will continue warming:

The IPCC report predicts that surface temperatures will continue to rise.Sea levels will rise:

Sea levels are predicted to rise … rise by between 26 and 82 centimetres (cm).

Oceans will become more acidic

Earth System Models project a decrease in surface ocean pH by the end of 21st century

Information taken from:IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the

Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)].

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IBDP Biology SL Activity

Activity 2: Your evaluation of Climate change articles

The nature of the scientific method is that a hypothesis should be supported by a plausible explanation and data, from an experiment which is repeatable by other researchers, then peer reviewed.

This process of objectively collecting data to support or refute a hypothesis is essentially the difference between philosophy and science. There are some areas of science where experiments are hard to do and other areas where the data are not easy to interpret. Climate change is one of these, there are so many factors which can influence the climate and it is nearly impossible to control many of the variables. For this reason the evidence for climate change is still contested by some groups.

Use this table to evaluate the three articles below.

Least reliable better Most reliable

The publication

Website, blog or letter from a private individual

A respectable newsletter or website

Quality media, newspaper

Textbook or Science magazine

Peer reviewed journal or governmt report

Status of the Author

Unknown individual

Well informed person

Professional or expert in another discipline

Scientist working in climate science

Recognised expert in the field

Supporting Data / evidence

None given Small sample or preliminary study

Single good study, lacking details

Good methods, large sample, extended period of time

Two or more high quality studies with matching results

Scientific explanations

None Untested Hypothesis

Hypothesis compares favorably with others

Theory agreed by most of scientific community

Scientific theory or law widely accepted.

Evaluating Claims about Climate Change

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IBDP Biology SL Activity

1. Global warming stopped 16 years ago, reveals Met Office report quietly released... and here is the chart to prove it

By David Rose Published: 21:42 GMT, 13 October 2012

The world stopped getting warmer almost 16 years ago, according to new data released last week. The figures, which have triggered debate among climate scientists, reveal that from the beginning of 1997

until August 2012, there was no discernible rise in aggregate global temperatures.

This means that the ‘plateau’ or ‘pause’ in global warming has now lasted for about the same time as the previous period when temperatures rose, 1980 to 1996. Before that, temperatures had been stable or declining for about 40 years.

Read more: http://www.dailymail.co.uk/sciencetech/article-2217286/Global-warming-stopped-16-years-ago- reveals-Met-Office-report-quietly-released--chart-prove-it.html#ixzz30H1YXVLv

EvaluationUse the table to evaluate this article then explain your evaluation using words from the table.

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IBDP Biology SL Activity

2. "Despite Uncertainties, Need to Confront Climate Change Clear," Kerry Emanuel, PhD , Director of the Program in Atmospheres, Oceans, and Climate at the Massachusetts Institute of Technology (MIT), Feb. 15, published in the Boston Globe :

"Concentrations of the two most important long-lived greenhouse gases, carbon dioxide and methane, have been increasing since the dawn of the industrial era; carbon dioxide alone has increased by about 40 percent. These increases have been brought about by fossil fuel combustion and changes in land use...

Global temperatures have been rising for roughly the past century and have so far increased by about 1.4 F. The rate of rise of surface temperature is... larger than any natural change we have been able to discern for at least the past 1,000 years.

Disputes within climate science concern the nature and magnitude of feedback processes involving clouds and water vapor, uncertainties about the rate at which the oceans take up heat and carbon dioxide, the effects of air pollution, and the nature and importance of climate change effects such as rising sea level, increasing acidity of the ocean, and the incidence of weather hazards such as floods, droughts, storms, and heat waves. These uncertainties are reflected in divergent predictions of climate change made by computer models...

But when the dust settles, what we are left with is the evidence. And, in spite of all its complexity and uncertainties, we should not lose track of the simple fact that theory, actual observations of the planet, and complex models - however imperfect each is in isolation - all point to ongoing, potentially dangerous human alteration of climate."

Evaluation…………………..................................................................................................................

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3. "MIT Professor's Climate Change Op-Ed Proven False,"

William Gray, PhD, Professor Emeritus of Atmospheric Science at Colorado State University, Apr. 7, 2010, available at Heartland Institute Website (The mission of the Heartland Institute is to discover, develop, and promote free-market solutions to social and economic problems.)

"A high percentage of meteorologists and/or climate scientists do not agree that the climate changes we have seen are mostly manmade. Thousands of us think the larger part of the climate changes we have observed over the last century are of natural origin. I believe most of the changes that have been observed are due to multi-decadal and multi-century changes in deep global ocean currents. Such changes have yet to be properly incorporated into the global models or into most climate modelers’ thinking...

Many scientists believe a slightly warmer world would be, in general, more beneficial for humanity. The small changes in climate we have seen so far and the changes we will likely see in the coming decades are not potentially dangerous. It has been noted that vegetation growth is enhanced by higher CO2 levels.

The global climate models will never be able to replicate the complex global atmosphere/ocean environment and its continuing changes...

We should all call out faulty science wherever we see it, including the blind belief (without any evidence beyond the faulty models) that humans are largely responsible for climate change."

Evaluation…………………..................................................................................................................

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Can you see any examples of ‘blind belief”, mentioned in the last line, in the article itself?

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4. Cayman Islands Coral Reefs Experiencing Dramatic Comeback

January 21, 2014

Bonner R. Cohen Bonner R. Cohen is a senior fellow with the National Center for Public Policy Research, (read full bio)

In a stunning example of the natural world’s remarkable ability to bounce back from ecological decline, the coral reefs surrounding Little Cayman Island in the Caribbean Sea—all but written off as dead by some marine scientists a decade ago—are rapidly regaining their health.

Back to Pre-Bleaching LevelsBleaching, blamed by global warming activists on warmer ocean water, and the spread of infectious disease, took a heavy toll on the reefs around the turn of the century. From 1999 to 2004, live coral cover declined by more than 40 percent. But a 13-year study conducted by the University of Florida and Caribbean researchers and released in November 2013 found the amount of live coral on the reefs, the density of young colonies critical to the reefs’ future health, and the overall size of corals have returned to 1999 levels.

The original study “A Positive Trajectory for Corals at Little Cayman Island”, Carrie Manfrino, Charles A. Jacoby, Emma Camp, Thomas K. Frazer, Published: October 09, 2013 in the online periodical Public Library of Science.

Evaluation…………………..................................................................................................................

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Describe the difference between the Author of this article and the Researchers of the study publisher in PLOS?.....................................................................................................................................

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5. Global warming slows coral growth in Red SeaDate: July 16, 2010 Source: Woods Hole Oceanographic Institution

In a pioneering use of computed tomography (CT) scans, scientists at Woods Hole Oceanographic Institution (WHOI) have discovered that carbon dioxide (CO2)-induced global warming is in the process of killing off a major coral species in the Red Sea. As summer sea surface temperatures have remained about 1.5 degrees Celsius above ambient over the last 10 years, growth of the coral, Diploastrea heliopora, has declined by 30% and "could cease growing altogether by 2070" or sooner, they report in the July 16 issue of the journal Science.

"The warming in the Red Sea and the resultant decline in the health of this coral is a clear regional impact of global warming," said Neal E. Cantin, a WHOI postdoctoral investigator and co-lead researcher on the project. In the 1980s, he said, "the average summer [water] temperatures were below 30 degrees Celsius. In 2008 they were approaching 31 degrees."

D. heliopora did not exhibit one of the typical signs of thermal stress: bleaching. "These corals looked healthy," said Cohen. but CT scanning of the coral's skeletal structure in the laboratory revealed "the secrets that the skeletons are hiding," she said. "The CT scans reveal that these corals have actually been under chronic stress for the last 10 years, and that the rates of growth were the lowest in 2008," the final year of the study

The full paper is : Neal E. Cantin, Anne L. Cohen, Kristopher B. Karnauskas, Ann M. Tarrant, and Daniel C. McCorkle. Ocean Warming Slows Coral Growth in the Central Red Sea. Science, 16 July 2010: Vol. 329. no. 5989, pp. 322 - 325 DOI: you can read a shorter summary in Science Daily

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