From Newsgroup: uk.sci.weather

Best fit quadratic marginally over indicial.
Also linear and exponential checked, ie no acceleration, fixed
acceleration, increasing acceleration and reducing acceleration.

Data from
https://gml.noaa.gov/webdata/ccgg/trends/ch4/ch4_mm_gl.txt

y= a +(b)*x +c*x*x +d*sin(2*3.141593*x+e) + f*sin(g*x+ h)

a= 1772.165350
b= -0.720193
c= 0.293845
d= 5.391505
e= 1.713943
f= -0.314943
g= -9.208144
h= 11.019126

y in ppb and x = year minus 2000,
6 figure values retained for anyone else checking/confirming all this
For 11 Dec 2025 output (data to Aug 2025). The offline curvefitter at statpages.info had difficulty converging with 2 variables for the
annual speeds, so 2*Pi used for one, as well as being limited to 8
parameters , although holding one while optimising 8 and swapping over
is possible, but messy.

Ignoring the SH and NH sine components
From 11 Dec 2025 output ( for 2003 data up to Aug 2025) for 2050
projection , 2470.768 global CH4, decrease of 34.0 ppb ( over the last year)
No processing Jan 2025 to Nov 2025
From 05 Dec 2024 output (data up to Aug 2024) for 2050 projection ,
2504.789 global CH4, decrease of 10.7ppb (2 months separation of outputs)
Nov data not processed
From 08 Oct 2024 output (data up to June 2024) for 2050 projection ,
2515.476 global CH4, decrease of 5.2ppb (2 months separation of outputs)
From 05 Aug 2024 output (data up to apr 2024) for 2050 projection ,
2520.715 global CH4, increase of 0.4ppb
From 08 Jul 2024 output (data up to Mar 2024) for 2050 projection ,
2520.330 global CH4, decrease of 1.3ppb
From 05 Jun 2024 output (data up to Feb 2024) for 2050 projection ,
2521.676 global CH4, increase of 3.4ppb
From 06 May 2024 output (data up to Jan 2024) for 2050 projection ,
2518.307 global CH4, decrease of 6.6ppb
From 05 Apr 2024 output (data up to Dec 2023) for 2050 projection ,
2524.913 global CH4, decrease of 3.5ppb
From 06 Mar 2024 output (data up to Nov 2023) for 2050 projection ,
2528.368 global CH4, increase of 0.1ppb, highest projection of this metric.
From 05 Feb 2024 output (data up to Oct 2023) for 2050 projection , 2528.294ppb global CH4, increase of 3ppb.
From 05 Jan 2024 output (data up to Sep 2023) for 2050 projection ,
2525.487 ppb global CH4, increase of 1ppb.
From 05 Dec 2023 output (data up to Aug 2023) for 2050 projection ,
2524.649 ppb global CH4, increase of 12ppb.
From 06 Nov 2023 output (data up to July 2023) for 2050 projection
forwards, 2512.115 ppb global CH4, decrease of 4ppb.
From 10 Oct 2023 output (data up to June 2023) for 2050 projection
forwards, 2516.113 ppb global CH4 (decrease about 4 ppb, a significant decrease, perhaps a yearly filter effect as last year there was a large
drop and then the following month a complete reversal )
From 06 Sep 2023 output (data up to May 2023) for 2050 projection
forwards, 2520.200 ppb global CH4 (increase about 0.3 ppb)
From 08 Aug 2023 output (data up to Apr 2023) for 2050 projection
forwards, 2519.949 ppb global CH4 (increase about 1 ppb)
From 05 July 2023 output (data up to Mar 2023) for 2050 projection
forwards, 2519.166 ppb global CH4 (increase about 0.8 ppb)
From 05 June 2023 output (data up to Feb 2023) for 2050 projection
forwards, 2518.408 ppb global CH4 (increase 1 ppb)
From 09 May 2023 output (data up to jan 2023) for 2050 projection
forwards, 2517.873 ppb global CH4 (increase 2 ppb)
From 05 Apr 2023 output (data up to dec 2022) for 2050 projection
forwards, 2515.77 ppb global CH4 (increase 3 ppb )
From 06 Mar 2023 output (data up to nov 2022) for 2050 projection
forwards, 2512.28 ppb global CH4 (increase 5 ppb )
From 06 Feb 2023 output (data up to oct 2022) for 2050 projection
forwards, 2507.56 ppb global CH4 ( increase 4 ppb)
From 06 Jan 2023 data, for 2050 projection forwards, 2503.47 ppb global
CH4 (increase +3ppb, back to Oct 2022 projected level)
From 07 Dec 2022 data, for 2050 projection forwards, 2500.31 ppb global
CH4 (decrease -2ppb)
From 07 Nov data, for 2050 projection forwards, 2502.32 ppb global CH4 (decrease -3ppb)
From 06 Oct data, for 2050 projection forwards, 2505.15 ppb global CH4 (increase +26 ppb)
From 06 Sep data, for 2050 projection forwards, 2478.72 ppb global CH4 (decrease -27ppb)
from 06 Aug data, 2506.16 ppb global CH4 (increase +1ppb)
from 11 July data, 2505.27 ppb global CH4 (increase +5ppb)
from 06 June data, 2500.61 ppb global CH4 (increase +4ppb)
from 05 May data, 2496.26 ppb global CH4 (increase +5ppb)
from 07 Apr data, 2491.42 ppb global CH4 (increase +7ppb)
from 08 Mar 2022 output gives 2484.94 ppb global CH4 (increase +4)
from 07 Feb 2022 output gives 2480.69 ppb global CH4 ( increase +11)
from 06 Jan 2022 output gave 2469.27 ppb global CH4 ( increase +4)
Dec 2021 output gave 2465.43 ppb (slight decrease -1, lowest
projection for this metric with up to july 2021 data, 6 months after
minimum of ENSO ONI)
Nov 2021 output gave 2466.0 ppb (first such determination)
--
Global sea level rise to 2100 from curve-fitted existing altimetry data <http://diverse.4mg.com/slr.htm>
--- Synchronet 3.21a-Linux NewsLink 1.2