Answer
The electric field just outside the Earth's surface would point radially inward.
Work Step by Step
We can find the surface area of the Earth:
$Area = 4\pi~R^2$
$Area = (4\pi)~(6.37\times 10^6~m)^2$
$Area = 5.10\times 10^{14}~m^2$
We can find the total charge of this number of electrons:
$Q = (-1.6\times 10^{-19}~C)(5.10\times 10^{14})$
$Q = -8.16\times 10^{-5}~C$
An electric field points toward a negative charge.
Since the charge on the Earth's surface is negative, the electric field just outside the Earth's surface would point radially inward.
