7.3.5 Global Warming

In this lesson, we will explore some of the biological consequences of global warming, particularly in relation to the increasing levels of carbon dioxide and methane.

Impact on Ecosystems

Global warming refers to the long-term increase in Earth's average temperature due to the accumulationChange in a physical quantity over time, whether that be an increase, decrease, or no change at all. of greenhouse gases in the atmosphere.

• Changes in Species Distribution: Rising temperatures can cause shifts in the geographic range of plant and animal species. Some species may move towards higher latitudes or higher elevations to find suitable climates, while others may become locally extinct.
• Phenological Changes: Global warming can disrupt the timing of seasonal events such as flowering, migration, and reproduction. Plants and animals may exhibit altered phenology, affecting the synchronisation of ecological interactions and potentially disrupting food webs.

Ecosystem ServicesIntangible products that provide a skill, experience, or benefit rather than a physical item.

Impacts on Pollination:

• Changes in the timing of flowering and the availability of pollinators due to global warming can affect the pollination process.
• This can lead to reduced crop yields and impact the reproduction and survival of flowering plant species.

Effects on Ecosystem Stability:

• Global warming can disrupt the delicate balance within ecosystems, potentially leading to reduced biodiversity and ecosystem instability.
• Species that are more sensitive to temperature changes may struggle to adapt, resulting in cascading effects on other species within the ecosystem.

Ocean Acidification

Increased Carbon Dioxide and Marine Life:

• As carbon dioxide levels rise, the oceans absorb a significant portion of this gas, leading to ocean acidification.
• Acidic conditions can negatively impact marine organisms such as coral reefs, shellfish, and other species with calcium carbonate structures.

Implications for Marine Food Webs:

• Changes in the chemistry of seawater can affect the availability of nutrients and impact the productivity of phytoplankton, the foundation of marine food webs.
• Disruptions in the base of the food chain can have far-reaching consequences for higher trophic levels, including fish populations and other marine organisms.

Methane and Global Warming

Methane Emissions:

• Methane is another potent greenhouse gas that contributes to global warming.
• It is released through natural processes, such as the decay of organic matter, as well as human activities like agriculture, fossil fuel extraction, and waste management.

Amplifying the Greenhouse Effect:

• Methane has a stronger warming effect per molecule compared to carbon dioxide, although it is present in lower concentrations.
• Its contribution to global warming is significant, particularly in the short term.

Conclusion

The increasing levels of carbon dioxide and methane in the atmosphere contribute to global warming, resulting in various biological consequences. Changes in species distribution, phenological shifts, impacts on ecosystem services, and ocean acidification are among the key effects of global warming on living organisms. Understanding these biological consequences is essential for developing strategies to mitigate the impacts of climate change and preserve the health and functioning of ecosystems.