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Human influences on ecosystems

Human influences on ecosystems

The actions and activities of humans that have a significant impact on the environment and the balance of ecosystems.

Climate change

The long-term alteration of temperature and weather patterns on Earth, primarily caused by human activities such as burning fossil fuels and deforestation.

Depletion of biological resources

The reduction or exhaustion of natural resources, including plants, animals, and other biological materials, due to human consumption and exploitation.

Loss of biodiversity

The decline or extinction of different species within an ecosystem, often caused by human activities such as habitat destruction, pollution, and overfishing.

Scientific journals

Publications that contain research articles and studies written by scientists and experts in a specific field, providing a platform for the dissemination of scientific knowledge and findings.

Peer review process

The evaluation of research papers by experts in the same field to ensure the quality, validity, and reliability of the research before it is published.

Scientific conferences

Gatherings where scientists and researchers in a specific field come together to share their findings, discuss ideas, and collaborate on advancing scientific knowledge and understanding.

Correlation

A statistical relationship between two variables, indicating that changes in one variable are associated with changes in another variable.

Causal relationship

A cause-and-effect connection between two variables, where changes in one variable directly result in changes in the other variable.

Temperature proxies

Indirect measures or indicators used to estimate past temperatures, such as tree rings, ice cores, and peat bog data, providing insights into historical climate patterns.

Greenhouse effect

The trapping of heat in the Earth's atmosphere by certain gases, such as carbon dioxide and methane, which leads to an increase in global temperatures.

Evidence of rising global temperatures

The IPCC graph (fig B) shows that global temperatures have been rising based on data from over 1200 temperature proxy records going back 1300 years, without using tree-ring data, and using two different statistical methods.

Atmospheric carbon dioxide levels

The Mauna Loa curve (fig E(a)) shows that atmospheric carbon dioxide has increased from 315.98 ppmv in 1959 to 381.74 ppmv in 2006, representing a percentage increase over time.

Ice core data

The Law Dome ice cores (fig E(b)) provide data on carbon dioxide concentration and show similar trends to temperature curves, providing further evidence of changing carbon dioxide levels.

Methane emissions

Methane is a potent greenhouse gas with a 72 times greater warming effect than carbon dioxide over 20 years. Methane is produced from the decay of organic material and the digestion of ruminant herbivores, such as cows. Human activities, such as rice production and increasing cattle populations, contribute to rising methane levels.

Cows and methane emissions

Cows produce methane through burping, with estimates ranging from 100 to 700 dm3 per cow per day. Livestock, including dairy cows, contribute to about 16% of methane emissions from human activities.

Strategies to reduce methane emissions from cows

Research teams are exploring breeding or engineering new strains of grass that can be easily digested by cows to reduce methane emissions. Keeping cows alive and healthy for longer can also reduce average methane emissions. Adding concentrates to the cow's diet can make digestion easier, but the manufacturing process may produce carbon dioxide, requiring a balance.

Correlation vs

There is a close correlation between the rise in greenhouse gases, such as carbon dioxide, and the increase in global temperatures. However, determining whether greenhouse gases cause rising temperatures or are a result of rising temperatures is challenging.

IPCC's conclusion

The IPCC concludes that there is a 95% probability that human activities contributing to greenhouse gas build-up are at least partly responsible for the observed increase in global temperatures. They state that human influence has been the dominant cause of global warming since the mid-twentieth century.

Impact of climate change on ecosystems

Climate change, caused by rising temperatures, can affect the distribution of species worldwide. It can lead to changes in weather patterns, including extreme weather events, alterations in rainfall patterns, and increased risk of flooding.

Thinning of polar ice

A clear indication of global warming and potential cause of flooding.

Antarctic ice melting

In 2002, 500 billion tonnes of ice broke away from the Antarctic peninsula and melted into the sea.

Arctic sea ice retreat

The Arctic sea ice has been retreating by about 2.7% each decade since 1978.

Sea level rise

Melting ice and warmer water will increase the volume of water in the seas and oceans, causing sea levels to rise.

Impact on human life

Around 100 million people live less than 1 meter above current sea levels, and the rise in sea levels could have immense implications for their lives.

Effect of temperature on organisms

Temperature affects enzyme activity, growth, reproduction, and survival of organisms.

Threat to species in the tropics

A change of just 1 °C could threaten the survival of up to 10% of all species, especially those in the tropics.

Changes in species distribution

Climate change can affect the range and distribution of organisms, leading to shifts in populations and potential extinction.

Spread of disease

Global warming could lead to an increase in insect-borne diseases, such as mosquitoes, ticks, and rats.

Depletion of biological resources in farming

Farming practices, including monocultures and artificial fertilizers, can deplete soil minerals and biodiversity.

Depletion of fish stocks

Overfishing, fishing at the wrong times, and destructive fishing techniques are depleting fish populations worldwide.

Anthropogenic changes in the ocean

Changes in environmental conditions, such as temperature, pollution, and predator populations, can impact fish populations.

Conservation conundrum

Balancing human needs and conservation is challenging, as industrial-scale farming and fishing provide livelihoods for many people.

Sustainability and resource management

Effective management is necessary to halt the depletion of biological resources and ensure a decent standard of living for future generations.

Human activities and climate change

Human activities, such as deforestation and greenhouse gas emissions from industries, contribute to climate change.

Conservation of fish stocks

Efforts are needed to conserve and sustainably manage fish stocks to prevent their depletion and protect ecosystems.

Mesh Size Control

Adjusting the size of fishing nets to only catch the largest fish.

Breeding Season Ban

Prohibiting fishing during the breeding seasons of different fish.

Strict Quotas

Imposing strict limits on fishing fleets and individual vessels.

Eco-friendly Fishing Methods

Encouraging the use of fishing methods that are less harmful to ecosystems.

Endangered Species Ban

Prohibiting the catching of severely endangered fish species.

Fish Farming

Cultivating fish and seafood through aquaculture methods.

Aquaculture Success

Fish farming as a successful means of providing people with desired fish and protein.

Global Impact

Around 47% of fish consumed worldwide comes from aquaculture, helping protect wild fish stocks.

Environmental Concerns

Fish farms contribute to greenhouse gas emissions and use non-sustainable fish-based feed.

Alternative Feed

Exploring the use of marine algae and other ingredients to reduce the environmental impact of fish farming.