{"id":68898,"date":"2023-07-07T00:05:58","date_gmt":"2023-07-07T04:05:58","guid":{"rendered":"https:\/\/world.edu\/?p=68898"},"modified":"2023-07-07T00:05:58","modified_gmt":"2023-07-07T04:05:58","slug":"why-are-so-many-climate-records-breaking-all-at-once","status":"publish","type":"post","link":"https:\/\/world.edu\/why-are-so-many-climate-records-breaking-all-at-once\/","title":{"rendered":"Why are so many climate records breaking all at once?"},"content":{"rendered":"

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In the past few weeks, climate records have shattered across the globe. July 4 was the\u00a0hottest global average day on record<\/a>, breaking the new record set the previous day. Average sea surface temperatures have\u00a0been the highest<\/a>\u00a0ever recorded and\u00a0Antarctic sea ice extent the lowest<\/a>\u00a0on record.<\/p>\n

Also on July 4, the World Meteorological Organization\u00a0declared El Ni\u00f1o<\/a>\u00a0had begun, \u201csetting the stage for a likely surge in global temperatures and disruptive weather and climate patterns\u201d.<\/p>\n

So what\u2019s going on with the climate, and why are we seeing all these records tumbling at once?<\/p>\n

Against the backdrop of global warming, El Ni\u00f1o conditions have an additive effect, pushing temperatures to record highs. This has combined with a reduction in aerosols, which are small particles that can deflect incoming solar radiation. So these two factors are most likely to blame for the record-breaking heat, in the atmosphere and in the oceans.<\/p>\n

It\u2019s not just climate change<\/strong><\/h4>\n

The extreme warming we are witnessing is in large part due to the El Ni\u00f1o now occurring, which comes on top of the warming trend caused by humans emitting greenhouse gases.<\/p>\n

El Ni\u00f1o<\/a>\u00a0is declared when the sea surface temperature in large parts of the tropical Pacific Ocean warms significantly. These warmer-than-average temperatures at the surface of the ocean contribute to above-average temperatures over land.<\/p>\n

The last strong El Ni\u00f1o was in 2016, but we have released\u00a0240 billion tonnes of CO\u2082 into the atmosphere<\/a>\u00a0since then.<\/p>\n

El Ni\u00f1o doesn\u2019t create extra heat but redistributes the existing heat from the ocean to the atmosphere.<\/p>\n

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Moderating the trend in global average surface temperature over time (1985\u20132022), La Ni\u00f1a (blue) has a cooling influence, while El Ni\u00f1o has a warming influence (red). Volcanic eruptions (orange triangles) can also have cooling effect. Dana Nuccitelli, using data from Berkeley Earth, author provided<\/p><\/div>\n

The ocean is massive. Water covers 70% of the planet and is able to store vast amounts of heat due to its\u00a0high specific heat capacity<\/a>. This is why your hot water bottle stays warm longer than your wheat pack. And, why 90% of the excess heat from global warming has been\u00a0absorbed by the ocean<\/a>.<\/p>\n

Ocean currents circulate heat between the Earth\u2019s surface, where we live, and the deep ocean. During an\u00a0El Ni\u00f1o<\/a>, the trade winds over the Pacific Ocean weaken, and the upwelling of cold water along the Pacific coast of South America is reduced. This leads to warming of the upper layers of the ocean.<\/p>\n

Higher than usual ocean temperatures along the equator were recorded in the first 400m of the Pacific Ocean throughout June 2023. Since cold water is more dense than warm water, this layer of warm water prevents colder ocean waters from penetrating to the surface. Warm ocean waters over the Pacific also lead to increased thunderstorms, which further release more heat into the atmosphere via a process called\u00a0latent heating<\/a>.<\/p>\n

This means that the build up of heat from global warming that had been hiding in the ocean during the past La Ni\u00f1a years is now rising to the surface and demolishing records in its wake.<\/p>\n

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From the surface to 400 metres deep, the Pacific Ocean along the equator is heating up. Bureau of Meteorology, Author provided<\/p><\/div>\n

An absence of aerosols across the Atlantic<\/strong><\/h4>\n

Another factor likely contributing to the unusual warmth is a reduction in\u00a0aerosols<\/a>.<\/p>\n

Aerosols are small particles that can deflect incoming solar radiation. Pumping aerosols into the stratosphere is one of the\u00a0potential geoengineering methods<\/a>\u00a0that humanity could invoke to lessen the impacts of global warming. Although stopping greenhouse gas emissions would be much better.<\/p>\n

But the absence of aerosols can also increase temperatures. A 2008 study concluded that 35% of year-to-year sea surface temperature changes over the Atlantic Ocean in Northern Hemisphere summer could be explained by\u00a0changes in Saharan dust<\/a>.<\/p>\n

Saharan dust levels over the Atlantic Ocean have been unusually low lately.<\/p>\n

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Agree with @MichaelEMann<\/a> — the dearth of Saharan dust over the tropical North Atlantic is helping drive the ongoing ocean heatwave. Dust concentration running low much of 2023, but at record lows (since 2003) for early June. Wrote about this last Monday: https:\/\/t.co\/4sM2YTJV4m<\/a> https:\/\/t.co\/6cEMBrxdvp<\/a> pic.twitter.com\/O7d4lgolRN<\/a><\/p>\n

\u2014 Michael Lowry (@MichaelRLowry) June 11, 2023<\/a><\/p><\/blockquote>\n