- cross-posted to:
- climate@slrpnk.net
- cross-posted to:
- climate@slrpnk.net
Leading scientists worldwide delivered a striking dose of reality to the United Nations on Sunday: it’s “becoming inevitable” that countries will miss the ambitious target they set eight years ago for limiting the warming of the Earth.
The ominous estimate points to the growing likelihood that global warming will shoot past 1.5 degrees Celsius before the end of this century, inflicting what scientists describe as an overwhelming toll from intensifying storms, drought and heat on people and the economy. It also injects an urgent message into global climate talks in Dubai, where the debate over ramping down fossil fuels is set to flare over the next two weeks.
Surpassing the temperature threshold — even temporarily — would be a major blow to the international Paris climate agreement from 2015, which called for nations to keep global temperatures well within 2 degrees Celsius of their preindustrial levels, and within 1.5 degrees if at all possible. The findings come amid climate talks that for the first time are focused on taking stock of whether almost 200 nations are meeting that goal. Early indications offer a bleak picture.
why are they the coolest months? northern hemisphere sure but aren’t we overall closer to the sun planet wise. I would think northern hemisphere summer would be the coolest.
The Southern hemisphere’s temperatures in winter (jun-sep) aren’t as cold as the northern hemisphere ones, so it makes sense the global average coldest temperatures are when the northern hemisphere is in winter .
For reference, only the Southern tip of south America gets snow in winter in the souther hemisphere
https://upload.wikimedia.org/wikipedia/commons/9/92/Annual_Average_Temperature_Map.png
Still don’t see how it matters given the whole globe. I would think globally being closer to the sun would be all that matters.
I understand where you are coming from, but the context necessary for it to make sense is that you don’t have to operate following the assumption that the seasons work the same for each hemisphere, one actually has a colder winter than the other, so that would affect the global average with a bias for the colder one. Think of it this way: the average winter temperature for the Southern hemisphere is not as cold as the average winter temperature for the northern one, so when taking them both into account for the global average, the temperatures in the north are going to skew the results (the Southern winter is not enough to offset the high temperatures of the northern summer, so the global average of the earth in its entirety is colder during the northen winter)
As to why that happens, well you are right that distance to the sun is one of the biggest factors for temperature, but it’s not the only one. Global climate is a dynamic system, with a lot pf variables interacting with one another. Things like ocean currents and the amount of landmasses play a big role in regional climates. For example, thanks to the ocean currents Europe enjoys a milder climate than it would given its latitude. In this case the Antarctic cold is unable to go north due to being sealed by the Antarctic current, which encircles the continent. Also, the Southern hemisphere has a lot less landmass than the northen one, and water is a temperature regulator, so that affects the climate down here as well.
From what I remember (it’s been over a decade since I read it), the southern hemisphere has much more water than the north.
Water is a great heat battery, especially deep oceans. And there’s a gigantic mass of water in the south. So in the summer it stays cooler because that mass of water can store a lot of energy, and in the winter it stays much warmer because the oceans slowly releases the heat that they have stored.
All that water mass is essentially “dampening” the climate extremes. And since ocean water also slushes around + evaporates in much greater mass than the little water on land, heat also gets redistributed better than on land.
So in short: more water = cooler in the summer + warmer in the winter.
The northern hemisphere has more land, so I would guess that affects how much sunlight gets absorbed
The ocean absorbs a ton. It’s one reason the ice caps melting is so bad. Ice reflects 90% while water absorbs 90%.
This is key. We might not notice it as quickly as on land, but water holds so much more energy than air. A warm ocean has a lot more and longer effect than warm land, even tho people are inclined to downplay it. The amount of heat required to increase the ocean with 1 degree is staggering.
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