Earth’s hottest month: these charts show what happened in July; what comes next
nature.com
nature.com
It shows average temperatures month by month, peaking in summer months, cooler in winter months. As expected.
Except that the graph says this is a global mean temperature, not just the northern hemisphere.
I would expect that the earth, on average, from north pole to equator to south pole, would, on average day, have about the same mean temperature, as it gets the same amount of total sunlight overall, regardless of the tilt of the earth. We're essentially on a sphere, and it gets the same sunlight coverage even though some points get more light than others.
I mean it's not like the earth gets less overall sun just because it's winter in the north.
So for whatever reason the entire earth is warmer when the northern hemisphere is experiencing summer? Am I interpreting that right? How is that possible, and what am I failing to take into account?
Does it have something to do with the elliptical orbit of the earth, and possibly that our closest yearly approach to the sun just happens to align with summer months in the northern hemisphere?
[1] https://media.nature.com/lw767/magazine-assets/d41586-023-02...
Yes.
> How is that possible, and what am I failing to take into account?
There are factors like that most of the landmass is in the northern hemisphere, we are in a strong El Nino, ships have to burn fuel with less sulphur and so on. Right now the factors involved are unclear but there is an unsettling possibility: The Earths climate might drastically and quickly change at so called tipping points, after which a new balance becomes the norm. This new balance may or may not be hospitable or even habitable for us.
> Does it have something to do with the elliptical orbit of the earth, and possibly that our closest yearly approach to the sun just happens to align with summer months in the northern hemisphere?
Nope, our orbit is very round and if this was a major factor we'd see it in historic data.
What does 'moderation' mean? The solar energy has to go somewhere, I'm assuming that's temperature. Are you saying it's not going into temperature, but instead being stored some otherway (like evaporation causing an increase in potential energy as the molecules rise?).
To me it's a question of energy input from sun - energy reflected and radiated out. Something like
temperature = constant * (energy from sun - energy reflected - energy radiated)
Water happens to have some of the highest specific heat capacities. Therefore, the south can "store" more energy in the hot months, and release that same energy in the cool months better than the north can
Thank god we have these big wet heat sinks available to help keep climate stable.
So, this, as well as ocean mixing is how the surface temperature is "moderated", in addition to the heat capacity that others have brought up.
So in the southern hemisphere with that much water, some of the energy goes into the phase change between water/steam. Much less so in the northern hemisphere.
Thank god we have these big thermal sinks (ice/water) to hold a lot of this energy to keep temp a little more stable.
Follow up question: I'm assuming the exact same thing applies with ice->water. So some of the energy hitting the earth is going into melting the ice instead of increasing temperature. It would seem to follow that, once all the sea ice and glaciers have melted, that this phase-change effect is removed, and therefore the temperatures will increase faster as none of the excess energy is going into ice->water phase-change?
Do they predict the temperature rise to increase once all of the sea ice and glaciers have melted?
Or maybe once it's water it just means that there is that much more liquid water available to evaporate into humidity?
Also, anyone know how the Canadian wildfires impacting the equation? Is that a potential explanation for the several sigma deviation this year?
Yes, and it's even worse than that. The ice also reflects and awful lot of energy back into space due to being highly reflective. When that the ice is gone, that exposes darker surface which is a lot less reflective. That will also result in lot more heating.
The more things warm up, the more things will warm up in a vicious cycle with many positive feedback loops. Sadly a lot of it seems irreversible at this point.
The first assumption is there’s a linear relationship, this is false. Also, X energy always moves from X to Y temperature, this also false. (https://en.wikipedia.org/wiki/Specific_heat_capacity etc)
Also it seems like energy reflected/radiated should be a constant or even a direct function of temperature, this is also false. (https://en.wikipedia.org/wiki/Albedo etc)
Undergraduate thermodynamics is complicated, but Earth is even more so because energy moves around quite a bit and the atmosphere is complex. Wind and ocean currents make a huge difference, as do cloud cover, and …
temperature = constant * (energy from sun - energy reflected - energy radiated)
Temperature is not 'the leftover energy'. The Earth is broadly in equilibrium.
It's more like
delta_temperature = constant * (energy from sun - energy reflected - energy radiated)
This Veritasium video gives a good idea of what we do get from the sun, if not 'net energy in': https://www.youtube.com/watch?v=DxL2HoqLbyA
If you look at the annual temperature range for the northern hemisphere (NH) it has a range >10C, while the southern hemisphere has a range ~5C.
You can read more about this here: https://www.carbonbrief.org/guest-post-why-does-land-warm-up...
** Since 1850
Why do these articles always try to sensationalize things? You lose credibility when you create clickbait headlines.
My understanding is temperatures recorded before about 1880 are unreliable[1]. This article does not provide a source for where their data comes from.
[1] https://climate.nasa.gov/faq/21/why-does-the-temperature-rec....
https://arctic-news.blogspot.com/2023/08/two-tipping-points....
Climate change is coming, and it's probably going to be coming faster than it ever has in Earth's history.
But note that this is only true for the part of Antarctica near the South Pole. As Antarctica is quite large, there are still parts that lie even today just north of the Arctic Circle.[1] Between the Antarctic Circle and the South Pole the length of the polar night gratually increases.[2]
[1] https://en.wikipedia.org/wiki/Antarctic_Circle#/media/File:A...
[2] Wikipedia has a nice graph showing the effect for each latitude: https://en.wikipedia.org/wiki/Daytime#/media/File:Hours_of_d...
Even in the temperate zones, agricultural zones will shift tens or hundreds of miles toward the poles, where the growing seasons will be shorter due to daylight. Centuries of infrastructure will have to be rebuilt from scratch, if it can be done at all.
The tipping points have the potential to be globe-spanning catastrophes. But even if we get lucky and none of them happen, there are disastrous effects that we are absolutely certain about.
Or maybe we happen to be at tail end of Little Ice Age and gradual change will continue.
Pole ice has not grown back enough; pole ice reflects heat back into space, while naked sea will absorb it.
Permafrost has been melting in the northern regions, making thousands of years of sequestered and frozen biomass defrost and decompose, releasing huge amounts of methane.
Sea flow (whatever it was called) that pulls warm water north and cold water south, balancing out temperatures, is slowing down because of heating up + desalinization (from melting glaciers). When I read about it years ago, it said that that's what causes an ice age (as in, ice sheets going south).
It almost feels like a conspiracy: the part of the world that is ideologically predisposed to disbelieve in climate change is also the one that is (partly) avoiding it. And that part is the linchpin: other places are disinclined to do the hard work of fixing the climate while the US prominently denies that the problem even exists.
It's as if the earth wanted to keep warming.
Obviously not, of course, and I don't really know if it really figures into it one way or the other. But it still strikes me as weird. How different would the situation be if the US midwest and south were on the hotter side of the scale, rather than the cooler one?
Besides, getting folks to recognize the impacts of climate change is one thing, convincing them that the threat is such that any impactful fix would require fundamental and drastic changes to their comfortable lifestyle is a whole different conversation.
This investment will likely bring in a positive return on investment because it reduces the negative climate impacts.
With recognising climate change, I feel the issue is many people, focus on the short term for what is a long term issue. In the way people say the climate change isn't happening, to them it's not. Individuals will see fairly limited change over a single lifespan, but what we do today will likely have a huge impact to people 100+ years from now. Often media/activists presents climate change as this imminent threat year after year, which isn't true as the climate is a slow ship, and while actions is absolutely needed for the future, I think many people see these endless imminent threat predictions not occuring, so to them this seems over dramatic and therefore untrue.
I often have similar thoughts: if you expand the scope a bit and don't limit yourself to the metrics that are the topic du jour - this is not meant to diminish the severity of heatwaves, to the contrary -
it seems like a natural law that the people who do the most damage to common goods (such as humane shelter and food, clean water, clean air, healthy environment, bearable noise pollution, bearable working conditions if you want to go there) - they are the people who profit and stand exactly on the other side, experiencing the absolute minimum of the damage they cause.
This is a prisoners's dilemma or market failure that has infested all of our global society, to a point that we can't even start to imagine.
I think we will continue to live as we do until we cannot. Then there will be a natural correction. It will probably be ugly for a while, then we will adapt. This is the history of the planet.
Do you think humans use oil, soil etc as efficiently as ants do?
Or do you mean "consumption" when you say "use"? The way you put it sounds like you mean
use ~= utility
There are just so many speakers and writers and thinkers with their own side of the prisoner's dilemma in mind
"A 'greenhouse Earth' is a period during which no continental glaciers exist anywhere on the planet... Earth has been in a greenhouse state for about 85% of its history... Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously."
You don't warm the earth rapidly (which at this point we undeniably are) and then magically get back "normal" fern forests and dinosaurs or whatnot. What you get is a mass extinction.
Eventually, things will evolve to forests or the equivalent. You'll be unlikely to have the same kinds of dinosaurs as before, but as the old saying goes, nature like carcination. There will probably be new variants of crabs.
You seem to be saying the equivalent of e.g. "It's OK to kill all the elephants because in a few million years something else will have filled the niche". That seems ridiculous to me.
Does your logic extend to all species? All ecosystems? Our species?
In fact what you're describing is exactly the disconnect: libertarianism is very much not "conservative" by traditional standards. The fact that they live in the same party in the modern US is an accident; it doesn't follow from their philosophies at all.
If the effect of global warming were felt equally in the US and that somehow caused the US to halt 100% of their emissions it would reduce global emissions by about 11% [1].
1: https://www.cnbc.com/2021/05/06/chinas-greenhouse-gas-emissi...
See: https://www.cgdev.org/media/developing-countries-are-respons...
China is the world's factory, 20% of the US imports come from there, of course your own country doesn't pollute much when you gutted half of your industries and relocated them in foreign countries.
edit: don't forget per capita greenhouse emissions too, in that case Americans emit twice as much as Chinese https://www.worldometers.info/co2-emissions/co2-emissions-pe...
Estimates are that only around 10% of Chinese carbon emissions are for foreign exports: https://www.sciencedirect.com/science/article/abs/pii/S09596....
And you can't deny that the US and EU has been moving in the right direction, while China is moving in the wrong direction.
US carbon emissions peaked in 2000 and have been moving down ever since. China's carbon emissions have grown by 500% during that time period. https://www.macrotrends.net/countries/USA/united-states/carb...
They are uniquely bad in this regard, compared to their peers like India and other developing economies. It's clear that China does not care about climate change in the slightest.
Here it says 33%: https://www.newscientist.com/article/dn14412-33-of-chinas-ca...
> They are uniquely bad in this regard, compared to their peers like India and other developing economies.
Of course India is nowhere close to China, they basically don't exist in term of exports. These countries have almost nothing in common besides having a large population
https://statisticsanddata.org/wp-content/uploads/2021/07/Top...
https://en.m.wikipedia.org/wiki/List_of_countries_by_exports
> while China is moving in the wrong direction.
You sure about that ?
https://www.statista.com/graphic/1/267233/renewable-energy-c...
Again it's easy to pollute less when you literally shut down all your industries. You can't ask for more and more growth, cheaper and cheaper prices and 0 pollution.
> China does not care about climate change in the slightest.
Not more or less than 99% of countries on this earth, including the US and most of Europe. If they did they'd have stopped their Chinese imports a long time ago, as well as most of their exports and massively reduced their energy usage (daily reminder than the average US household uses 4 times more energy than a German one)
Yes, China built six times the number of coal plants of the entire rest of the world last year. Six times! It's inexcusable.
https://www.npr.org/2023/03/02/1160441919/china-is-building-...
Meanwhile the US has mothballed half of it's coal plants in 10 years:
https://www.eia.gov/electricity/annual/html/epa_04_01.html
> Here it says 33%
You're clearly cherry picking very old data (2008) that is not published research to try and make a point here. The references aren't even comparable.
> If they did they'd have stopped their Chinese imports a long time ago
Plenty of people would be delighted to embargo China due to their environmental record. If that's what you're proposing, we agree.
There is more nonsense in this statement than in the headline. Parts of the world don't have ideology and these highly judgmental and superficial analysis certainly don't help.
> other places are disinclined to do the hard work of fixing the climate while the US prominently denies that the problem even exists.
So, China's inability to manage pollution is somehow down to the imputed attitudes of a few areas of the US?
> It's as if the earth wanted to keep warming.
It's as if human beings exist and continue to multiply. It's as if third world countries don't care about our ideology if it means they never get a chance to develop themselves the way every other country had an opportunity to. It's as if a few rich people half way around the world expect the difference to be made up elsewhere.
> But it still strikes me as weird.
It's purely anecdotal.
> How different would the situation be if the US midwest and south were on the hotter side of the scale, rather than the cooler one?
Texas had the hottest summer in recent history. California had one of the mildest. Minnesota had one of the hottest and they're getting Canadian wildfire smoke.
Perhaps we shouldn't view this through the lens of "how miserable do we have to make people to get change to happen" and instead through the lens of "how incompetent are our politicians that they can't find an honest solution to this problem?"
This _desire_ for self-inflicted austerity is what is _weird_.
Edit: because another way to view the lens you dismiss is “how miserable do people need to get before they accept that something real is happening here?”
The largest voting block could stop war emissions by replacing Biden with RFKjr or even Trump. Huge carbon savings there.
I'd guess that for most people in the US they are more likely to notice that than to notice a change in average temperature. Consider someone in a place that normally gets cold enough to require heat for much of the winter and hot enough to require air conditioning for most of the summer.
Someone could easily not notice a 3℃ increase in average temperature that manifests as winter being a little less cold, summer being a little warmer, and winter being a little shorter, and summer a little longer because their HVAC system keeps their would at a fixed temperature all year around.
Their energy bill would go up, but they might think that is just due to inflation.
But if they start getting afternoon brownouts because of everyone's AC dealing with extreme summer heat, and that happens more and more each year, that is something they might notice
There was a recent article about record breaking temperatures in South America but it turns out the sensors they were monitoring had only been in place from 2008.
In short, although vineyards are an extremely bad proxy for the temperature record, even by the vineyard standard it is much warmer today in the UK than it ever was over recorded history.
It's just that we're living right now and not before the last ice age. Sucks for us.
https://www.cnn.com/2019/09/17/world/tambora-eruption-year-w...
"The global temperature dropped between one and three degrees Celsius. It was the coldest year in at least the last 250 years ... led to crop failure, the death of livestock and famine."
https://en.m.wikipedia.org/wiki/1815_eruption_of_Mount_Tambo...
Or, according to indirect proxy measurements, since the first agricultural revolution when humans started relying on stable climates with the invention of farming, and relying on stable sea levels by building large fixed settlements on the coasts, about 12,000 years ago.
Note that the article does mention this: "July 2023 was the hottest month in recorded history", "the average global temperature was 1.54 °C above the preindustrial average for July", etc... (emphasis mine). It's just that nuance tends to be missed in headlines.
Not that that's a good thing, but it's not like it's unique to climate reporting. If you want to have a go at editors for clickbait/hyperbolic headlines, you can probably find better examples in the politics or media coverage sections of whatever publications you prefer.
What's the point of this? Just to be "technically" right?
Sure in a technical sense the Earth will survive this change. It's a big ball of rock, a few degress of difference on the surface means nothing to it. For the plants and animals however we're talking about a mass extinction event.
Clearly the planet will be fine if temperatures keep rising, Earth has seen far greater catastrophes and temperature swings.
It remains to be seen whether humans will be fine if the climate keeps warming.