Examples

Running longterm with no arguments is boring because it will generate a time series representing a continuation of the preindustrial steady state. Below are some examples of more interesting simulations.

Constant radiative forcing

This simulation turns on a 1 W/m² top-of-atmosphere radiative forcing at t=0 and holds it on for all time thereafter.

• R
• Python

output <- longterm(sources=list(rad=1))

output = longterm.run(sources={"rad":1})

Nuclear winter

This simulation turns on a -500 W/m² top-of-atmosphere radiative forcing at t=0 that then decays with an e-folding timescale of 5 years, representing the effects of a severe nuclear winter.

• R
• Python

output <- longterm(sources=list(rad=function(t){ -500*(1-exp(-t/5)) }))

import math
output = longterm.run(sources={"rad": lambda t: -500*(1-math.exp(-t/5))})

Slug of fossil fuel

This simulation releases 5000 GtC of fossil carbon into the atmosphere as CO₂ at t=0.

• R
• Python

output <- longterm(sources=list(Cas=function(t){ if (t>0) { 5000 } else { 0 } }))

output = longterm.run(sources={"Cas": lambda t: 5000 if t > 0 else 0})