Episode 141: Natural Climate Change

Volcanic Eruptions

Volcanic eruptions play a crucial role in climate change by increasing Earth's albedo through the release of particulate matter and aerosols. James Fodor explains that large eruptions can cause significant cooling effects, although these typically last only a few years until the particulates disperse. He cites the 1816 eruption of Mount Tambora as an example, which led to the 'year without a summer' due to a noticeable drop in global temperatures 1.

Variations in volcanic activity, produced by tectonic plate activity, may explain some of the climate variations over millions of years.

--- James Fodor

However, individual eruptions are not long-lasting enough to explain recent temperature changes 1.

   

Silicate Weathering

Silicate weathering is a vital geological process that regulates the carbon cycle and impacts long-term climate change. James Fodor describes how carbon dioxide from the atmosphere dissolves in rainwater to form carbonic acid, which then reacts with silicate minerals to eventually form calcium carbonate 2. This calcium carbonate is deposited on the ocean floor, effectively removing carbon dioxide from the atmosphere.

The reverse process of metamorphism and volcanism returns carbon dioxide to the atmosphere.

--- James Fodor

These processes, influenced by factors like tectonic activity and temperature, act as a negative feedback mechanism for Earth's climate 3.