That's like 0.003X of a Chicxulub impacter. Or around 1X the geologically very recent eruption of Mount Toba.
The ecosphere will be fine. You'll probably vaporize a small patch of ocean, and they'll get colorful sunsets for a couple days. But that's about it.
By contrast, assuming "more or less today's technology", we're now out of petroleum reserves because we used them all in our magic instant-acceleration kinetic-energy-converter.
At the link below you can see simulations at 99.9% light speed. An entire Egyptian pyramid, hitting Earth at this 10x higher speed, might kill off life, but it’s still not obliterating the planet.
We are not capable of accelerating any macroscopic object to .999C. Let alone a huge piece of tungsten, which still wouldn’t be powerful enough.
I mean, the planet would exist, but it wouldn’t exactly be capable of sustaining life any more.