Based on a linear decline of the global Total Fertility Rate (TFR), humanity will go completely extinct in approximately 244 to 264 years, with the global birth rate hitting zero in exactly 143.75 years.1. Calculate annual TFR declineThe starting fertility rate is \(2.3\).It drops \(0.4\) every \(25\) years.\(\text{Decline\ Rate}=\frac{0.4}{25}=0.016\text{\ per\ year}\)2. Determine zero birth yearWe define TFR over time \(t\):\(T(t)=2.3-0.016t\)Set fertility to zero:\(2.3-0.016t=0\)\(t=\frac{2.3}{0.016}=143.75\text{\ years}\)Global births completely stop at \(143.75\) years.3. Add remaining human lifespanExtinction occurs when the last person dies.The maximum human lifespan is \(100\) to \(120\) years.Add this lifespan to the zero birth year:Lower estimate: \(143.75 + 100 = 243.75 \text{ years}\)Upper estimate: \(143.75 + 120 = 263.75 \text{ years}\)Final Projection ✅Under these specific parameters, humanity will go completely extinct in 243.75 to 263.75 years from now.If you want to refine this projection, let me know if you would like to:Switch to an exponential decay model.Factor in shifting global life expectancies.Analyze regional variations in demographic trends.

(http://www.autoadmit.com/thread.php?thread_id=5884737&forum_id=2Elisa#50016509)