Also, during the last 3 cycles, the temperature at the peak of a retreat period was 3-5°C (~5-9°F) hotter than current temperatures and at the peak of a glacial period the temperature was 3-9°C (~5-16°F) cooler than current temperatures. During the last 3 cycles, the sea level at the peak of a retreat period was about at current levels and at the peak of a glacial period the sea level was about 300-400 feet lower than current levels.

In the last 3 - 110,000 year glacial cycles, the CO₂ concentration peaked in the 280 to 320 parts per million (ppm) range. Based on current models that assume CO₂ levels in our atmosphere increases to 750 ppm from the current levels of about 350-400 ppm, some have estimated,that the current warming retreat period could be extended 50,000 years or more past the more normal 110,000 year cycle. Interestingly, from NOAA data, the peak warm temperatures of the last 3 - 110,000 year cycles were higher, even with lower CO₂ concentrations. During those last 3 cycles, the maximum CH₄ concentration and N₂O concentration were about 60% and 20% lower respectively. Maybe the CO₂ is not the biggest factor?

But, based on various reports, which Countries generate the most global CO₂ ?

1)     China (Mainland)                          25-30%

2)     United States of America             14-15%

3)     European Union                             9%

4)     India                                               7%

5)     Russian Federation                        5%

6)     Japan                                              4%

We could do a lot of things, very expensive things, to try to lower CO_{2 ,} but even if we completely halted ALL greenhouse gas emissions tomorrow, in the end, over the long term, it wouldn’t change a thing.  We could go into all sorts of greenhouse gas emission sources, greenhouse gas emission reduction scenarios, etc. but again, it most likely will not substantially change the temperature or sea level cycles that have happened about every 110,000 years in the past. And, academics say the world will run out of liquid hydrocarbon fuel in less than 100 years, and coal certainly within 200 years. Why kill our economy now, when all fossil fuels will be gone soon. In geologic and atmospheric time, 100 years in a 110,000 year cycle is just a 'blink of an eye'. Possibly these 110,000 year cycles are more due to the Earth’s varying orbit around the Sun or some inherent ‘resonance’ of the Earth’s temperature. Might the sea levels be higher this time, might the temperatures go higher this time since CO₂ is higher? Maybe. Based on many models, by 2250, a "best guess" sea level rise of 8” to 80” may occur, but anything we do now won’t change that. We could start right now and plant millions of trees each year to try to make up for the loss of rain forests and vegetation cut by man for farms, etc. and we could stop ALL fossil fuel use immediately, but, it would take well over 1,000 years to change things, if it did actually change things at all. It seems a bit arrogant to think we can change what has been occurring on Earth long before humans populated our planet, and we will run out of fossil fuels in the next 100-200 years anyway .  So, what can be done? We should prepare for the same effects seen in previous cycles, like further rise in sea levels, higher temperatures, etc., because those 3 most previous 110,000 cycles occurred long before the agricultural and industrial revolutions.  The changes may come more quickly this time, they may last longer this time, they may be a little worse this time, but Earth’s equilibrium will eventually occur and a new glacial cycle will begin.