[evan_au]

the amplitude of the seasonal variation exceeds the year-on-year cumulative change

Sure, and the daily variation in temperature exceeds the year-on-year cumulative change.
- And if you measure the temperature across the arrival of a cold front, the hourly variation in temperature exceeds the year-on-year cumulative change.

There are conceivable (but not yet understood) slight links between temperature and phase of the sunspot cycle.
- So, in my book, any temperature measurement averaged over a period of < 10 years is talking about weather, not climate.

[alancalverd]

I'd go along with that, but the periodicity of the Mauna Loa CO2 measurement is undeniably annual and very consistent in amplitude, with a peak every early summer for as long as the data has been collected.

Good science depends on explaining the facts, not ignoring those that question the hypothesis.

[JanetSims]

the amplitude of the seasonal variation exceeds the year-on-year cumulative change

Sure, and the daily variation in temperature exceeds the year-on-year cumulative change.
- And if you measure the temperature across the arrival of a cold front, the hourly variation in temperature exceeds the year-on-year cumulative change.

There are conceivable (but not yet understood) slight links between temperature and phase of the sunspot cycle.
- So, in my book, any temperature measurement averaged over a period of < 10 years is talking about weather, not climate.

Interesting observations, however, it is caused by humanity, isn't it?

[alancalverd]

No. Humans generate more CO2 in winter, not summer. That's what makes the Mauna Loa  data so  interesting: it suggests that CO2 is a thermometer, not a thermostat,

[Bored chemist]

No. Humans generate more CO2 in winter, not summer. That's what makes the Mauna Loa  data so  interesting: it suggests that CO2 is a thermometer, not a thermostat,

We have been here before.
The M-L data probably looked fairly similar before mankind evolved, a cyclic seasonal variation in CO2.
The difference we have made is that it's now superimposed on a slope that's going up faster than ever before.

CO2 isn't a thermostat; nobody said it was.

[alancalverd]

a slope that's going up faster than ever before.

...than ever before Mauna Loa began to collect data, true.

If you remember vinyl records, you might recall that the microscopic scratches in an inch of one groove didn't look much like Beethoven's Sixth. At the time of recording, they may have been very important to the trombonist playing at that moment, but they don't tell you where Beethoven fits in the grand scheme of music.

[HaelSturm]

I hope as we humans continue to learn about the impact of climate change on our planet, we will also figure out new ways to counter its effects..

[alancalverd]

Most of us would be prepared to use past data, models and analogies.
Alan would insist on an experiment.

Or an honest look at past data.

[William Hardy]

I feel to most extent, yes.
https://doaj.org/article/001a0722364944189808a861792fe644

[acsinuk]

The article indicates that emerging economies are causing an increase in CO2 as they need to build more houses and factories and infrastructure for an expanding population.
Most advanced nations with high standards of living like Sweden have a declining population so only need maintain homes and infrastructure so are low CO2 emissions.  Surely poor nations with low standard of living need only restrict their population growth to automatically raise their standard of living and help save the planet.

[Bored chemist]

Surely poor nations with low standard of living need only restrict their population growth to automatically raise their standard of living and help save the planet.

Did you think that was  a viable answer or are you joking?

[alancalverd]

It contains one element of the truth. Poverty arises from demand exceeding resources, and from mismanagement. You can tackle the first cause by making fewer babies. The second usually requires a revolution.

[JimmyW9]

Perhaps all processes on earth are cyclical. Indeed, the world is warmer now. I remember when I was a child, every year in my city there was a lot of snow and it was quite cold. Now the winters are mostly warm, it rains. But I think this will change in a few decades.

[alancalverd]

Climate certainly is cyclic.

 have a look at http://www.climatedata.info/proxies/ice-cores/,  particularly fig 5

[acsinuk]

"EPICA Dome - Temperature and Milankovitch Cycles" Figure3 shows how the quantity of gases CO2 and Methane that are trapped in the ice can be measured and from these global temperature at that time can be calculated.
So if the scientists at the south pole compress a sample of snow into ice and test it what were the readings last year compared to the ones taken 100 years ago I am wondering???

[alancalverd]

The data is available but we also have direct measurements of local temperature and near-global CO2 certainlyh form 50 years ago and possibly 100 years ago, which may help to calibrate the ice cores.

There is a problem with sampling recent Antarctic snow: there has been a lot of human and mechanical activity  on the continent in the last century, so even if you sample from a previously unvisited area the snow will contain a whole lot of contaminants that weren't present in the deeper ice cores.

[acsinuk]

Yes, I understand that there will be lots of contaminants but what is required is to confirm how many parts per million of CO2 are in the latest samples.  Does it positively confirm the rise seen in the atmospheric gas in the northern hemisphere?

[Petrochemicals (OP)]

Given temperatures are rising, co2 has historically risen along side it. No one is sure of the cause, it could be as simple as higher temperatures mean higher decomposition, or it could be something more complex where increasing temperatures are merely a sign of more complex chemical interactions at work, such an increased geological co2 release because of a softer and more pliable earth crust. My compost bin is getting quite full, come the summer it will no doubt shrink once more.

Funnily enough the historic data is not precise enough to state factors are out of the ordinary, the margin of error is great. Personally I believe that the planet is warming in line with the historic trends.

[Peter11]

8 billion humans 3 to 4 billion cars driven daily over a hundred thousand flights a day industry pumping it out.We also have overrun every habitat.I think we can say for sure we are responsible and blind to our imprint.We are going to hit peak population very soon  things will only get worse the more humans there are.Its amazing how many people have blinders on  8 billion humans  and growing some how have no effect on the environment.

[alancalverd]

Yes, I understand that there will be lots of contaminants but what is required is to confirm how many parts per million of CO2 are in the latest samples.  Does it positively confirm the rise seen in the atmospheric gas in the northern hemisphere?

AFAIK there has been an overall increase in CO2 concentration wherever it is measured, and little need for recent ice core studies as pCO2 has been measured directly since the 1900s.

What we do know from satellite surveys  is that the concentration is not evenly distributed, with odd pools of high density around the equator, for instance, where anthropogenic output is presumably less than over Europe and North America
 https://www.bbc.co.uk/news/science-environment-30399073