# globalwarmingindex.org

Tracking progress to a safe climate

Human-induced warming: ---------------- °C
Total Carbon Dioxide emissions: ---------------- trillion tonnes
(Equivalent tonnes of Carbon: ---------------- tonnes)
Other Human influences on climate: ---------------- Watts per square metre

on now

Why are we now providing three numbers?

Human-induced warming (ΔT) over a time-interval ranging from seconds to decades is proportional to total cumulative carbon dioxide emissions over that time-interval (ECO2) plus the impact of any change in global energy imbalance due to other human influences on climate (ΔFother).

We can write this as an equation [1]: $${\color{red} {ΔT}} = {\color{blue}κ} ⋅ \left( E_{CO_{2}} + {{ {\color{grey} { ΔF_{other} }} } \over {\color{blue}α}} \right)$$
where κ is the “Transient Climate Response to Emissions” (about 0.4°C per trillion tonnes of CO2 [2]) and α is the “Normalised Absolute Global Warming Potential” of CO2 (about 1.0 W/m2 per trillion tonnes of CO2 [3]).

Don’t take our word for it: add them up and check! Now you know what’s causing global warming.

# Current Global Warming Index

The first graph shows an index of human-induced global warming relative to the second half of the 19th century (1850-1900).

The second graph shows index together with the associated CO2 and other forcing contributions.

globalwarmingindex.org is provided by the Oxford University Environmental Change Institute.

See here for further details about the graphic above.

[1] Allen et al, npj Clim Atmos Sci 1, 16 (2018)
[2] Myhre et al (2013) in IPCC 5th Assessment Report, incl. uncertainty range of 0.23-0.68°C/TtCO2.
[3] α = AGWPCO2/H, where H is the AGWP time-horizon. Myhre et al (2013) give values of 0.9-1.2 W/m2 per trillion tonnes of CO2 in the 20-100 yr range.