Skip to 0 minutes and 10 seconds The planet’s climate has constantly been changing over geological time in response to natural factors. Over tens of thousands of years, we’ve seen the Earth run in and out of ice ages. However, over the course of the last century, there has been an abnormal increase in the Earth’s average temperature. This warming is occurring more rapidly than many past events. Scientists are concerned that the natural fluctuation or variability is being overtaken by a rapid human-induced warming that has serious implications for the stability of the planet’s climate. So why do scientists believe this warming is induced by humans? There is evidence that most of the warming is due to an increase in greenhouse gases in the air, known as the greenhouse effect.
Skip to 1 minute and 0 seconds The greenhouse effect refers to the way the Earth’s atmosphere traps some of the energy from the sun. Solar energy radiating back out to space from the Earth’s surface is absorbed by atmospheric greenhouse gases and re-emitted in all directions. The energy that radiates back down to the planet heats the lower atmosphere and the surface. Without this effect, the Earth would be about 30 degrees Celsius cooler, making our planet hostile to life. Scientists believe we’re adding to the natural greenhouse effect with gases released from industry and agriculture, known as emissions. These gases trap more energy and increase the temperature. This is commonly referred to as global warming or climate change. Greenhouse gases include water vapor, carbon dioxide, methane, and nitrious oxide.
Skip to 1 minute and 55 seconds Since the Industrial Revolution began in 1750, carbon dioxide levels have risen by more than 30%, and methane levels have risen by more than 140%. The concentration of carbon dioxide in the atmosphere is now higher than at any time in at least 800,000 years. The average global temperature has increased by almost one degree Celsius in just over a century. The degree of warming that has occurred in the last 200 years is about the same variation we have seen over the last 10,000 years. The amounts of snow and ice have diminished. Sea levels have risen. And we have seen extremes of weather, such as heatwaves and heavy rainfall. These levels cannot be explained by natural processes.
Skip to 2 minutes and 42 seconds And scientists believe the predominant cause of the observed warming has been due to human activity. So how will climate change affect us? The scale of the potential impacts of climate change is uncertain. The changes could drive freshwater shortages, bring extensive changes in food production conditions, and increase the number of deaths from floods, storms, heat waves, and droughts. Plant and animal extinctions are predicted as habitats change faster than species can adapt. Some coastal areas on islands, such as the Marshall Islands in the Pacific, are at risk from rising sea levels. And the World Health Organization has warned that the health of millions could be threatened by increases in malaria, water-borne disease, and malnutrition.
Skip to 3 minutes and 33 seconds Arguably, the most fundamental impact of global climate change on the human population is, and will continue to be, on the food production systems. The chemical, biochemical, and microbiological safety of food is a diverse field, heavily influenced by changes in the environment, both natural and anthropogenic. Changes and weather patterns are likely to entail changes to crop yields. The threat from mycotoxins may intensify as the climate becomes more suitable for disease development. Fish stocks are already impacted by over-fishing and are under increasing pressure from changing climatic conditions. The rising sea temperatures may make traditional habitats no longer suitable for the current species.
Skip to 4 minutes and 22 seconds Pests and diseases continue to systematically move north as environmental conditions change, making the introduction of novel pest’s species such as invasive insects, weeds, or fungi highly likely. Control responses may generate food safety problems due to the novelty of the pests in question and unfamiliarity of farmers in dealing with them. It is therefore important for us to understand how the provision of safe food and the promotion of good food safety practices across the food chain will be affected.
Climate change is one of the greatest challenges of the 21st century. The atmosphere and oceans have warmed, sea-levels have risen, there is a strong decline in Arctic sea ice and other climate-related changes are evident.
Arguably, the most fundamental impact of global climate change on the human population is its effect on the food production system, with potential consequences predicted to:
Entail changes to crop yields
Make conditions more suitable for disease development
Intensify the threat from mycotoxins
Add pressure to the already struggling wild fisheries sector
Make traditional habitats no longer suitable for the current species
Allow pests such as insects, weeds or fungi to continue to systematically move north and make the introduction of novel pest’s species highly likely.
Control measures initiated in response to climate change may generate food safety problems due to the novelty of the climate-induced issues (e.g. new pest species) and the unfamiliarity of farmers in dealing with them. It is important for the food chain to understand how this will affect the provision of safe food and food safety practices.
Please watch the video and share any thoughts that you have about climate change in the discussion area below.