No, more like 50%, at least according to this study:
Attribution of the present‐day total greenhouse effect
Gavin A. Schmidt, Reto A. Ruedy,Ron L. Miller and Andy A. Lacis
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115, D20106, doi:10.1029/2010JD014287 , 2010
abstract:
The relative contributions of atmospheric long‐wave absorbers to the
present‐day global greenhouse effect are among the most misquoted
statistics in public discussions of climate change. Much of the
interest in these values is however due to an implicit assumption that
these contributions are directly relevant for the question of climate
sensitivity. Motivated by the need for a clear reference for this
issue, we review the existing literature and use the Goddard Institute
for Space Studies ModelE radiation module to provide an overview of
the role of each absorber at the present‐day and under doubled CO2.
With a straightforward scheme for allocating overlaps, we find that
water vapor is the dominant contributor (∼50% of the effect), followed
by clouds (∼25%) and then CO2 with ∼20%. All other absorbers play only
minor roles. In a doubled CO2 scenario, this allocation is essentially
unchanged, even though the magnitude of the total greenhouse effect is
significantly larger than the initial radiative forcing, underscoring
the importance of feedbacks from water vapor and clouds to climate
sensitivity.
.pdf here. See also the RealClimate article (written by Gavin Schmidt) here, which explains why the overlap in absorbtion makes the definition of the contribution of each gas difficult to define unambiguously, but the range of definitions mean that:
... it’s clear that water vapour is the single most important absorber
(between 36% and 66% of the greenhouse effect), and together with
clouds makes up between 66% and 85%. CO2 alone makes up between 9 and
26%, while the O3 and the other minor GHG absorbers consist of up to 7
and 8% of the effect, respectively.
Note that water vapour acts as a positive feedback because it is a condensing greenhouse gas (GHG) rather than a long-lived one, i.e. it doesn't accumulate in the atmosphere like CO2 does, as the amount of water vapour the atmosphere can hold depends on its temperature (Clausius-Clapeyron) so if excess water vapour is injected into the atmosphere, it quickly precipitates out again as rain/snow. Thus it is the CO2 that is responsible for the bulk of climate change, exacerbated by the positive feedback from the concomitant increase in water vapour.